Summer in Europe

You might find this a trip of a lifetime. And as young adults, you may be able to hold up to visiting more cities than normal. But my question is will you remember so many cities, or will it just be a blur?
I suggest splitting your trip into segments to cities that are (1) Close to each other with good train services, (2) Cities that compliment each other and (3) Cities that are full of young, highly spirited people.
I'm talking about a segment starting in Munich to Salzburg, Budapest, Vienna and Berlin.
Another segment would be Rome, Florence, Venice. Or, London to Paris on Eurostar and down to Barcelona on a fast train. We also love Amsterdam, a great, great city for young people.
I find flying on budget European airlines is a really cheap way to move longer distances--or to get into a different group of cities.
We find cruise ships can be very inexpensive and efficient ways to see deadly expensive cities--like Estonia, St. Petersburg, Helsinki, Stockholm, Copenhagen, Oslo, Bergen.

David
Thank you so much!! It’s a good idea grouping the countries into segments and I never thought about a cruise ship- I will have to look into that!

How exciting! I know I find planning my trip almost as much fun as the trip itself! I highly recommend Rick Steve’s book Europe Through the Back Door as a starting point. This will give you a rough estimate on expenses, budgeting and planning. It was a very valuable resource for me when I planned my first trip many, many years ago and his advice is still very relevant today. Big difference from my first trip so long ago is that now budget airlines make distant cities much more affordable and quicker to get to. Personally, I would take a quick flight over an overnight train any day! It may sound exciting but the reality was not quite as glamorous as I imagined! You will get many different opinions on where you should go and what you should see....do your research and see what inspires and appeals to you. Have a wonderful time!

don’t have a huge budget

Pretty vague.

A really rough guess is you should plan on not less than $150 per person per day to cover lodging ( assuming you share a room) food, admissions and local ground travel. All air travel would be additional.

You will need 3 months to hit all you wish for destinations

Go to something like booking.com and look at rates for the kinds of places you plan to stay to get a better idea of lodging cost. Overall food costs are going to be not much different there than in the US.

PS--With the exception of Monaco, everything you listed is not a country

I'd suggest getting a map of Europe and marking all those cities. Do you see isolated spots--cities that are hanging out there all by themselves, probably costing a good bit of money and time to reach? Those are places to consider cutting. One example is Copenhagen. Lagos is also challenging because ground-transportation links between Portugal and Spain are surprisingly poor.

On a budget you'd probably want to stay outside Monaco (maybe in Nice), and I wouldn't go all the way to southern France just to see Monaco, so that would be on my list of places probably to cut unless further research indicates that there are a lot of other places you want to see in that area.

Switzerland is not by any stretch a budget destination, so I'd nix Bern for now. Even if you find lodgings in youth hostels, you'll still have to deal with Swiss rail fares and food costs. You can visit Switzerland in the future when your finances are not so tight.

You mostly have capital cities and big-name destinations on your list. To the extent that you spend time in smaller places, you will save money. You'll also often be in less touristy environments, which makes a nice change from the big cities with Starbucks, KFC and McDonalds all over the place. Everyone wants to hit the places they've heard of on their first trip (my list looked a lot like yours), but you'll see more if you spend more time in each area and less time on trains and buses chewing up the miles. There are fabulous destinations near every one of the places you list.

For major cities like most of those you list, I'd figure on at least 4 nights. That will be tight for some of them (Rome, Barcelona, Berlin, Budapest) but will be OK-to-generous for Venice, Brussels, Athens, and Monaco. As you start learning more about all there is to see and do in the various destinations, you may decide to go to fewer places and stay in each one longer.

You should research Brussels. Not many people seem entranced by it, and it's a fairly expensive city.

The following places on your list have the potential to be quite hot, especially in July and August: Madrid, Rome, Venice, Amalfi Coast, Budapest, Prague, Vienna, Munich, Berlin, Athens and Greek Islands. Barcelona doesn't usually bake, but it can be humid enough that 80F doesn't feel so wonderful. That doesn't mean you shouldn't go to any of those places, but it would be smart to try to include some spots where you can cool off. I've done trips that included 1 - 2 months of high heat, and it gets very old and very tiring. If you find that your budget dictates youth hostels, that will be an additional issue, because I don't think they have air conditioning.

Climate change has resulted in heat waves in places that rarely, if ever, experienced such conditions in the past. But these areas are usually much cooler: England, Scotland, Ireland, Wales, Brittany and Normandy in France, the northern stretch of Spain from the Pyrenees to the NW coast, mountain villages at significant altitude, Denmark, Sweden, Norway, Finland, Estonia, Latvia, Lithuania, and the Baltic Coasts of Germany and Poland. (Unfortunately, Sweden and Norway are both rather expensive; I'm not sure about Denmark and Finland.)

For a rough idea of lodging expenses, use booking.com. Choose dates next summer and specify central locations in the larger cities. You'll see options from dormitory beds to apartments to hotel rooms. Be careful about Airbnb and similar platforms, whose listings often have substantial cleaning fees.

If you end up planning a trip that's close to 90 days, research the Schengen Zone to be sure you will not be violating the 90-day limit in that area.

15 countries, 8 to 12 weeks and neither of you have ever been out of the US before? Pare down your list. You're only going to be 21 & 18 when you take this trip so you've got decades of travel ahead of you. Rough rule of thumb - 1 country should equal a minimum 1 full week, otherwise skip it. If you can't devote at least 2 full days (not including arrival and departure days) to a location, cross it off your list. When you arrive in a new destination it will take you time to get your bearings. Consider every time you have to pack up and move, you lose half a day to a full day in transit. Every time you move around, it's costing you more money because you need to buy another train, bus or plane ticket. Decide if you want to go to Europe to really see and learn about the countries/cities you are visiting, or if you are there to snap selfies in front of something famous to post to social media to say you were there.

You've got scads of time to take out guidebooks from your local library on these countries, watch a bunch of YouTube videos and scour forums like Lonely Planet's ThornTree to gain perspective on which places to focus on. Get Europe through the Back Door and read it to understand how to develop a workable itinerary and just generally get advice geared towards new travelers.

Traveling in peak season prices are generally higher. Also, some places you rattled off can be pricey - Copenhagen, Bern, Amsterdam. Not to say they can't be done on a budget, but you are already stating you want to stay in hotels or Airbnb for privacy and safety. Rethink that. You could get a private room in a hostel, but consider an all-female quad room (you would make up 50% of that room, so you are talking about sharing with just 2 other travelers). Most hostels have private lockers to store wallets and electronics securely. You'll meet other people your age - something you aren't going to get if you stay at a hotel (even a budget one). I'd rather stay at a well-situated hostel in a dorm room than a 2 star hotel that's further out because I'm fretting over budget. Research hostels on review sites like Hostelworld.com to see what other people have to say and learn how to spot a well-run hostel vs. a lousy one - always check reviews for comments about location, safety, cleanliness and noise levels. Airbnb is only going to be private if you rent the entire place - otherwise, you are renting a bedroom in someone's home and that bedroom likely won't even have a lock on the door, so how is that any more secure? Also Airbnb listings sometimes have additional fees you must take into account as part of your budget - cleaning fees, security deposits, etc.

You have a long time to save money for this, so be realistic about budgeting for everything. Very roughly for lodging, I'd say consider something in the realm of 100 to 130 Euro per night for the 2 of you in a decent hotel or private room in a hostel. If you are willing to stay in a dorm room in a hostel, figure about 70 Euro for the 2 of you. Start giving yourself a reality check about what you need to budget for everything else based on your lifestyle at home - are you ok with fast food/cheap takeaway places/food trucks or are you going to want to eat in restaurants nightly?, how many Starbucks lattes do you need to get through the day right now? are you going to want to party in a chic bar or nightclubs on a regular basis where there are hefty cover charges and expensive cocktails, or are you more of a homebody who will spend nights relaxing back at your hotel getting ready for the next day? are you really interested in immersing yourself in lots of museums, cultural events or major sights that have admission charges, or are you more interested in just wandering and seeing what you find that's free? You don't know what the exchange rate will be in 4 years, so just assume the dollar isn't performing on par with the Euro and save more USD to offset it.

I find it very helpful to watch video programs about various destinations. The Rick Steve's videos are excellent for getting a taste for different countries. You can typically check them out from the library, or watch them online on PBS.com or they are all on Rick Steve's website, as well. He has MANY full length shows and some shorter videos as well. You can also look at other people's trip reports and just poke around on the RS website. Another thing you can do is make substitutions of similar cities for cities that tend to be crowded/expensive. Prague is super crowded, for example, and some people find Krakow to be a good alternative.

If you were to do Munich, Vienna, and Budapest, then Bratislava is close and is a more reasonable city to visit, price wise. I'm a parent of 4 kids in their 20s. They've loved Paris, Amsterdam, The Hague, Delft, Copenhagen, Bruges (not Brussels) Barcelona, Budapest, Vienna, Prague, Munich and Berlin.

I have a bucket list of cities that I'd like to go to and one thing I do is follow their weather on my Yahoo weather app. It also has very beautiful pictures of cities as well. I watch the weather in certain areas to get a feel for the time of year I'd like to visit. For example, Sevilla, Granada, etc., has been on my list and in fact I'm going in November. But, following their weather I noticed that they are frequently 100 degrees F in the summer! Madrid, Toledo and that area is often 90 degrees in the summer. I can't do that. But, I've noticed that the Basque area of France and Spain are quite lovely in the summer and early fall.

In terms of budget many places offer reduced rates with a student ID. You can consider having your main meal at lunch and buy your breakfast and dinner at bakeries and grocery stores.

I went the first time at the age you intend to do your trip, also in the summer, 12 weeks exactly, my first time out of Calif and out of the country too...solo. It was 1971 and I was 21. I would suggest planning on staying exclusively in hostels, university dorms (I only used that option a few times), and even camp sites. No problems with staying in HI or private independent hostels, which is still a possible option for me. Re transportation...use all the options, day and night trains, buses from city to city, ferries, discount carriers,

Be advised too that the more " amenities" you want, eg., air conditioning, privacy, etc, the more you end up paying.

I may have missed it in the previous responses, but you need to remember that you are limited to 90 days in the Schengen countries. The day you arrive and the day you leave both count against the 90. Most people who plan a long trip arrange to leave the Schengen countries around the 88th day, just in case there is a delay of some kind.

This is a link to more detailed information about the Schengen countries. You can match up your cities with them.

In these early planning stages, Rome2rio will help you understand how widely separated or grouped your cities are, the different kinds of transportation available to go between them and how long each type might take. The costs will be almost useless because your trip is so far into the future, and because Rome2rio is weakest on that prediction.

A long time ago, I read that you should plan to spend $150 - $180 per person, per day on a moderately priced trip. That's for everything except your international flight. I've found that's very accurate for self-planned trips. Tours cost more, but you get much more, too. Many on the forum travel much more cheaply than that.

Our son opted to cheap out when he took his daughters to Paris. I warned him about his hotel choice. It turned out to be such a dump that they packed up their stuff each morning and took it to lockers somewhere nearby.

Having said that, there are plenty of places that are clean, comfortable and reasonably priced. You just have to do your research to find them. Others have mentioned Booking.com to look for lodgings. They include hotels, B&B's and apartments along with other types. You can use multiple filters to choose the options that matter to you. I highly recommend that you use 8+ for the review score under Top Reviewed, no matter what your price range is. Obviously, the prices will be higher 4 years from now, but you can at least get some ideas of costs, maybe even for the same time of year you plan to go only in 2019.

One other note. Apartments that you find on one resource may also be listed on others. For example, the same place may be on Booking.com, VRBO, Homeaway, local city listings and Airbnb. If you compare prices, don't be surprised if Airbnb is the highest.

I have lower standards than Lo, so my cut-off point on booking.com is 7.0. I do read reviews very carefully, though, to be sure the reason for that not-high score is not something that really matters to me. (I want to be sure the air conditioning, Wi-Fi and hot water work, the place is clean, and the location is convenient for my sightseeing plans.) I haven't ended up with a dirty or decrepit room yet. Truly tiny, yes; view of an air-shaft, yes; dorm-room-style furniture, yes. And a range of annoyances (which I've also had in higher-rated places) like only 3 coat hangers, no stopper for the wash basin, etc. None of those problems are real-breakers when you're really pinching pennies.

I second many of the previous responses and I add my two cents:

• Where I'm getting into Plot your tentative itinerary in a map, in a physical map!, trust me, I am also techie but certain things you need to see physically, to really get a grasp of what it means -distances, grouping cities...
• Organising Split the trip into "blocks", grouping the cities you will visit. Note -and this is VERY IMPORTANT- that there's life beyond the city limits and you'll be missing many great spots if you only think about "the city of X or Y" -and this coming from an urbanite like myself, huh! So DO explore "what's around this or that city", quite often you'll find that day escapades allow you to see many different things and different landscapes without having to pack/unpack all the time. Example: this is merely 150 miles from Barcelona, and this at 25 miles... not saying you can do everything in a day, but you get my drift, right?
• When to travel Pick your season!... well, there are no longer seasons when it comes to big cities, they're always full of visitors, but it really makes a difference to visit one month or another: crowds, prices, etc. but, of course, there's always a trade off too: summer=heat, but more crowds, etc.
• Discounts Once you have your definitive list, check in each city whether there are schemes that you, as a student, could benefit from. For example, for Barcelona and all its region, Catalonia (think "state of") you should check up --sorry, not in the loop, I am no longer in that age range, LOL!-- if you're eligible for Carnet Jove (Catalan, the local language, for Youth Card) Also, at a European level there's something called The European Youth Card which has similar features, and lastly, there's also the International Student Identity Card, a scheme that has been working for decades offering discounts and numerous advantages to students travelling the world.
• Speaking Learning a few sentences in different languages is also advised... even if it's a simple "thank you" or "good morning" in the local language will take you a long way with the people of the land. For this, I advise a quick look at Wikitravel. For example, for Catalonia, my homeland, this would be a good starting point.
• Etiquette and manners You're going to be visiting different cultures so it's always a good idea to familiarize yourself with traditions, local manners, etc. so you're polite with your host countries and not offend anyone. Remember you're always a guest when travelling abroad, so it's important to behave as such and leave the "entitlement" home. Again, Wikitravel is helpful here, example.
• Budgeting No rule of thumb here as it depends on the city (not the country, the city!) you're visiting... thus some of them have a higher GDP and prices are, accordingly, more expensive, or sometimes because the place is very popular with visitors, prices are higher than expected. My advice for a first glimpse would be to make a list of "things" you're bound to do when visiting a city (ie riding the metro, getting a burger, visiting a museum, etc) and then have a look at Numbeo... it gives you a pretty realistic approach on average costs. Also, when you have your definitive list, drop by TripAdvisor and ask in the forum of each city...

And remember: travelling is fun, you get to know exciting places, astonishing cultures and wonderful people... but it requires some planning on your part, a lot of humility and the understanding you're not at home anymore -with all that entails.

Enjoy planning, it's part of the adventure!

The second city you list is Lagos.

It is in Nigeria in Africa.

Do you intend to expand beyond Europe into Africa or it a misspelling of somewhere else that I haven't guessed?

Nigel, I am ashamed at you. Lagos is in the Algarve, far south-west corner of Portugal. The one in Nigeria was named after the one in Portugal.

My comments to ecrawley:

• Be aware of the "90 days in any 180" limit for non-EU/Schengen citizens staying in the Schengen Area
• This is all cities (apart from "Island in Greece" - which one? and "Amalfi Coast"). Do you want to restrict yourself to cities, or see some countryside or mountains as well?
• You say "Here’s the list of options for countries" - but actually list cities (apart from Monaco!).
• It is a pretty random choice of locations. Why did you choose them, and not others? What are your preferences and likes?
• You need to say how much time (how many nights) you want to stay in each.
• Get a map of Europe (find one on the Internet and print it out), mark all your destinations on it and join the dots to find the best order to visit.
• Go to the DB website ( https://www.bahn.com/en/view/index.shtml ) and start looking up train times. Use a date one month form now, next years times are not yet published. This will give you some idea of what is practical, and where a flight is required.

Nope, never heard of the one in Portugal.

Then again we get a lot of news here in England about Nigeria.

So I’m currently a high school student but I am planning on spending a summer in Europe in college after I turn 21 (about 4 years from now)

With this statement as context, its still just a pipe dream (I hope not literally). 4 years from now, your sister will probably have a boy friend and not really care to hang with her older brother for 2 1/2 months. But then, you might meet someone else who does want to hang with you.

That said, planning can be fun. You can research how to get to all of these (or maybe some of these) places, as well as costs of hostels. Make up trial itineraries and sights you want to see. All the info is available on-line. Guide books are still good resources.

My daughter and her friend did their backpacking trip to europe just two years ago.. she turned 20 while on the vacation.. they went for about 11 weeks .

They flew into London and flew out of Paris.. a complete circle route through europe.. they too had a long list of places.. but in the planning process learned quickly about paring it down. Some places are not as easy to get to as others.. so off the list, some places are very expensive .. so off the list.. and some places were logistically speaking too much work to get to from the place they were before.. So .. start with a map and pin the places you want to see.. now .. plan the transport route

DO NOT RUSH OFF AND BUY A RAILPASS! it often works out cheaper and easier to get some point to point tickets in advance ( cheaper than last minute) and book a few inter europeon flights ( they can be cheap too.. even with extra fees for baggage.. but learn to read all conditions carefully before you buy , and buy well in advance for best deals ) .

I also did a three month trip when I was young.

So I will tell you this.. my most favorite places then were the islands in Greece.. this was a long time ago,, but loved Mykonos and Paros.. nowadays I keep Mykonos to only a few nights to transit to another island.. its SO expensive.. but there are so many cheaper ones to try( we now love Naxos). My daughter and her friend visited Santorini ( but stayed in Kamari.. not on top as that is $$$$) .. and they loved Corfu.

Stay at a few hostels.. some have private rooms.. those book fast so do research and book ahead for them.. its nice having communal kitchens to make some of your own food ,, saves you lots of bucks.. that you can then spend when visiting the more expensive cities in Europe.

Pare that list down.. dont even consider 1 night stays.. those are useless.. you dont want this to be a tour of train stations and airports right.. Id say a 3 night miniumum for most places ( which only gives you two FULL days at destination ) .. and for some places I wouldnt consider less than 5 nights ( only four full days really.. Rome etc)

Brussels.. hmm.. one of my less favored.. what exactly do you want to see there? List sights you think you want to see in each place.. that will give you and idea of time needed.

Berlins a great party city for younger folks..

Monaco is easy and cheap to see from NICE.. one euro bus ride.. staying in Monaco will kill your budget.. plus if you stay in Nice you can easily visit so many other seaside towns of french riveria .. easy and cheap by train .. ( its like 5 euros to Cannes.. )

A really rough guess is you should plan on not less than $150 per
person per day

Sorry, but this is not remotely realistic for a very young person unless they have substantial savings already or will have such savings by the time of travel. $150 per day multiplied by 90 days (roughly 3 months) equals $13,500. Can the poster find enough willpower to save that much money for the trip ahead of time? It's possible, but is it likely? If not, then I would not assume staying in normal hotels (like much more mature posters on this forum), but rather hostels, in order to shave as much of the lodging costs as possible. Something has to give to make the numbers work.

My advice to the poster is to start by reading books, doing research, prioritizing, and really narrowing down the places to visit. There is not enough info here to know what's actually doable. The biggest costs will be lodging and transport, plus the airfare to get there and back from the US.

First, I think it's awesome that you're making this a long-term goal. Yes, you have a long list that will need to be pared down - but that will happen as you get into the planning. My cousin did a five-week trip through Europe last summer, before she started college. She and a friend started in Paris and went to Nice (with a day trip to Monaco), Geneva, Milan, Frankfurt, Salzburg, Lake Bled, Zagreb, Dubrovnik and ended in Rome. They stayed with family friends in a few places, but mainly were in hostels - which, as others have pointed out, will be much more economical for you and your sister than hotels.

Everyone above has given you good advice, so I'll just add this: Your life will change so much in the next four years. I'm assuming you're a senior in high school, which means you probably don't even know where you'll be next year, let alone in four. I tell rising-college students that I'm jealous of them; you are just starting this great journey, which is so full of possibility. As for this trip - take a history class or two; it might help you decide what places truly interest you, and will give you a deeper understanding of them when you do visit. You'll probably have a foreign language requirement in college. Take one of the Big European Four (French, Spanish, Italian or German) - or take Polish, or Welsh. Look into your college's study abroad options. Research grants, like the FLAS (Foreign Language and Area Studies), that will - get this - PAY for you to spend the summer or year abroad. That's how I got to spend a summer in Dresden and three summers in Lublin, Poland.

Basically, right now you don't even know what you don't know - and that's great! Because it means you'll get to spend the next few years learning and dreaming about all these great places you'll visit. I hope you'll check back in with this forum when you start planning in earnest; it will be fun for us to see what you've decided.

It's not that hard for someone, like a typical student, to spend less than $150.
The Nomadic Matt blog suggests 40 to 70€ per day for food, lodging and transportation depending on city, country, season.
Buy a few guidebooks geared to student travel, like ones from the Let's Go series or perhaps ones from Lonely Planet or Rough Guide. If you check out the Let's Go site, note that Rick Steves generously gives an endorsement to their (competing) guide.

As you are planning and researching, keep in mind that because you are under 27, you are eligible for Youth Pass for rail travel. If you get that 2nd class and the extra bonus travel day, ie 11 days total, that is not a bad deal. Plan on using both the Youth Pass as well as point to point tickets...it all depends.

Right now these destinations are all ideas, romantic ones.

As you read and plan (and, check out "Europe through the back Door, a travel skills abd planning how to), they will become more like real places, with geography in between them, and specific characteristics.

Some are cheaper than others, some have better rail systems, some have better food, some are hard to get to, some have iffy weather.

That more than anything else will help you to plan a memorable trip.

Slow down -- you have at least three years to plan. Right now you are getting shotgun answer that are of little value to you.

Get -- Europe Through the Back Door -- Read it twice, take notes. -- Watch lots of travel DVDs. Get all of this from you local library so that it saves you money. Then in about a year when you have a very rough idea of what and where you are going, come back with specific questions. We will be waiting. Do your homework first. This site is not homework.

All Rick's travel videos are available to watch right here on this website. Here's the link.

4 years from now? You are a planner!

Do research on youth hostels for your lodging in the cities/towns/villages that interest you. They will stretch out your budget. Read reviews as some they are not the same. Watch travel programs including Rick Steves Europe and take notes. You can watch them on PBS as well as on YouTube.

Ceidleh referred you to Lonely Planet's Thorntree travel forums. I strongly encourage you to spend time there. Each forum has its "focus". RS is mostly middle-aged and older, mostly budget-minded with an eye to getting the best experiences and comfort for our money. Thorntree's folks are younger, more adventurous and want to travel light and stretch their money to the limit.

BTW, there's nothing unsafe about European hostels. Most are clean, reasonably comfortable, in good locations and most important, it's an opportunity to meet other travelers, exchange information, get tips and just get to know people from other places and cultures.

If you were interested in meeting some locals, you could look into couchsurfing. We've hosted many young (and old) travelers here in our home - from 19 to one lady who was in her late 70s. When we surfed, we had better luck finding hosts in 'smaller' places like Strasbourg, Augsburg, Bern, Genoa, Bologna as opposed to places like Rome (hosts get tons of requests) tho we did find hosts on the outskirts of Paris and London. I found Switzerland was the easiest to find hosts (which was good since it was so expensive).

But as a caveat - I think a huge number of couchsurfing hosts have switched to airbnb compared to when we surfed in from 2008-12, so I'm not sure it's as easy now to finds hosts. We generally airbnb now - we're older now and don't have to penny pinch as much - and I like to book our stays further out (it's hard to ask someone a few months ahead if you can stay - generally a week or two out is the norm - but if you travel a little more spontaneously, it could work in your favour).

Some very good hostels in Budapest, Vienna, Berlin, and Munich since these are places you're considering. I've stayed at hostels in Munich and Vienna. since 2009.

I am a 35 year old solo man traveler. I have been to Canada; London, England; and three cities in Italy. I stayed in All hostels. My reason for picking hostels instead of hotels, when available, is to increase my chances of having some minimal interaction with other English speaking solo travelers; whether I save money in hostels versus hotels is just a side effect, not my first consideration. Before my trips I make reservations for spaces in 4-bed hostel rooms, in hostels that have air-conditioning and in ones that seem like one of the nicest hostels available in terms of amenities and location.

On my previous trips I bought most of my food from grocery stores - good stores have a produce section and a deli counter where they sell certain prepared foods. See other threads on this site about being mindful of where is public you can and shouldn't eat. You can't just sit and eat in crowded like the Spanish steps in Rome or in the middle of Florence; you probably can eat on benches and in parks.

Borrow some guidebooks from the library. Write a detailed day-by day itinerary. List one, two, or 3 major sites or museums you want to visit each day of your trip - Justify why you want to visit each city and how many days you need in each of these cities. Each day can be labeled with the name of the day (Monday, Tuesday, and so on). You can skip writing dates, for now. Include your transportation from the airport to your first destination, to your second city, and so on. Figure out which cities you want to see first, second, and so on.

My 14 day trip to Italy in 2017 cost under $3,100 US dollars. I would have spent under $3,000 if I had not bought souvenirs, under $2,800 if I had not done expensive guided tours. $2,800 / 2 = $1,400. 12 weeks x $1,400 = $16,800; 16,800 (x 1.03^4) to account for approximately 3% yearly inflation = a rough ballpark estimate of $18,700 to under $19,000 per person for a twelve-week trip, 4 years from now.

An alternative to hostels are the European budget hotel brands. The Ibis hotels (there is Ibis, Ibis Styles, and Ibis Budget) from the giant corporate conglomerate Accor Hotels are pretty much everywhere in France and common in many nearby areas. Style-wise, they're big concrete boxes with IKEA-like furniture, but are generally secure, clean, and have acceptable to good beds. And many of them in warmer summer areas have air conditioning, often a rarity for hotels in that price range. When pricing out, remember that the quote is per room rather than per person like hostels often charge. Join their loyalty rewards program, and you may earn enough points on stays earlier in the trip that you can use to pay for some nights later on.

https://www.accorhotels.com/gb/usa/index.shtml

There are also some smaller of those kinds of chains like Premiere Inn in England and Motel One in Germany (though Motel One has caught on enough with young business travelers it's not as good of a deal as it used to be)

As you are considering hostels, in both HI and private independent hostels there are a few hours (I think two, maybe three) devoted to cleaning. This is the hostel's lock-out time, (Reinigungssperre)

On the foreign language requirement: Even if you do not have such a requirement, ie, that no foreign language is mandatory as it pertains to you, take one anyway and plug away at it. You cannot over learn.

I'm sorry but from your post I cannot deduce your gender and that makes a difference to the advice.

I too recommend that you look seriously into staying in hostels and don't reject the dormitory out of hand. I stayed in many hostel dormitories when I was in my twenties and thirties and I think it is a good opportunity to meet other people. If you are male, then you and your sister will probably be in separate dormitories and that makes it easier to meet other people. If you are female, then you will be in the same dormitory and that makes you less approachable.

Also: you say "we also live in the USA", but are you US citizens or do you have a European passport? If you have European passports the 90 day rule does not apply to you.

You might also inquire at your college whether they offer a study abroad program ... usually for either a semester or a whole year. Might be a relatively cost-effective way to at least begin your European travels.

If you want to learn about inexpensive lodging options in European cities, and see what you money will get you in each place (e.g., how much a hostel might cost vs. a cheap hotel), a great site is Eurocheapo. Also look at their budget tips for each city: https://www.eurocheapo.com/

I agree that starting with the Europe Through The Back Door book is good, but then look at resources more geared to travelers of your ages and interests, like the Thorn Tree forum. Rick's son Andy Steves has a company selling 3 day excursions to various European cities for college students, and his book, Andy Steves' Europe: City-Hopping on a Budget, has much more advice than Rick's books do about bars, clubs, hostels, etc geared to young adults: https://www.amazon.com/Andy-Steves-Europe-City-Hopping-Budget/dp/1631217968