First Trip to Europe in 12 days

your feelings are correct so cut Luxembourg out it is kind of an outlier. Stay in Antwerp or Ghent 3 days and just do a day in Brussels from Antwerp or Ghent. Stay in Amsterdam 3 days. just do a day in Reims.

Are days 1-12 actual on the ground days with your flight in/out days additional? Or is day 1 your arrival day and 12 your flight out day?

Presumably you are flying into Paris and out from Amsterdam?

As for what might be appropriate to eliminate, one would need to know what interests you and what you want to see.

Your 'feeling' is right. You have too much in too little time

How many nights do you have? Days disappear with travel between locations so your two days in Amsterdam becomes one or 1.5 by the time you arrive on Day 11. To get two full days anywhere you have to spend 3 nights.

Since I think you have perhaps 12 nights and you fly out on the 13th day, here is what I would advise:
- arrive Paris and stay 5 nights, take your day trip to Versailles
- pick one of Reims, Brussels or Luxembourg (expensive!) and spend 3 nights giving you two full days in whichever place you choose
- go to Amsterdam for your remaining 4 nights, three full days.

Wonderful. Key takeaway will be to shorten the list. I think I'll take Luxembourg and Reims out of the list. I will have 12 nights total flying in and out of Paris so I have to go back to Paris from Amsterdam. I anticipate it won't take me more than 10 hours to get to Paris from Amsterdam worst case scenario, so I plan on leaving Amsterdam early on day 12th so I can be at the airport in Paris on day 13th.

Since this is my first trip to Europe, I want to see major sightseeings, especially in Paris and Amsterdam.

Also, I plan on taking train and buses for my whole trip. Is it even realistic?

Since you are leaving from Paris, it would be better to leave Paris for the end of your trip. If possible, go immediately to your first town. You won't have to worry about getting back to Paris on the last day

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Do you have to fly round-trip Paris? Most of us who visit multiple locations in Europe fly open-jaw, into one city and out of another. That would save you having to return to Paris and losing much of a day to travel.

Reims is a reasonable day trip from Paris. I enjoyed it very much, though I did stay overnight.

If you have 11 or 12 nights on the ground, I think you could fit in 2 days in Belgium. I'd recommend staying in either Bruges or Ghent (I prefer Ghent and it's cheaper) for 3 nights, using one day for each town, then continuing on to Amsterdam.

The trip is doable even more if you dropped Amsterdam and keeping it focused on France, Belgium and Luxembourg.

No problem going to all places by train. When you go from Luxembourg to Brussels, I suggest going to Metz, then take the TGV to Paris Est. For Brussels the train leaves from Paris Nord. Logistically, it can be done if you plan out a few steps and know what you're doing.

Kelsi,
When are you going? Have you purchased your air tickets already? Depending on the sights you’re planning to see, many museums, especially in Paris and Amsterdam, are very popular and advance tickets are recommended. The Anne Frank Huis is an example. As of this past April when I visited, buying timed tickets online was required. Many sights in Paris have long lines to buy tickets so purchasing them in advance helps you skip the line. Food for thought as I don’t know what you are planning to see and do. Do you have a guidebook? Rick Steves has wonderful books filled with excellent tips that many of us on the forum use.

I’m sure you will have an amazing time.

First Trip to Europe in 12 days

Do you mean, the length of your trip is 12 days (and if so, do you mean 12 days from leaving your home to returning there, or 12 days on the found in Europe not counting your arrival or departure days - that makes a big difference on a short trip like yours),

Or do you mean your trip starts 12 days from now?

Or both?