France and Italy 3.5 weeks

3.5 weeks sounds like a lot, but your plan includes a very large number of places.
Example, doing Paris properly, you should plan on 5-6 days. Then doing the rest of France that you listed (I have done all that you listed), would take up two weeks.

Doing the plan in Italy could possibly be done in 3.5 weeks, but that would require skipping any other country.

This is your first trip to Europe, you might consider taking a group tour instead of doing it by yourself.
Taking a group tour like Gate 1 Travel or Rick Steves Tours you have the vast majority of your trip taken care of by the tour.
Lodging, transportation, day tours, most meals, etc are included.

Do it yourself, you will have to plan each day of your trip. Planning just what sites to book can be a pain. My wife and I did a week in Amsterdam three years ago and we had to book in advance admission to the Anne Frank House, the Rijksmuseum and Van Gogh museum. Also, we booked other day tours.

Just arranging transport can reqruire much planning. How do you get to your hotel from the airport. Booking taxis can be very expensive. We did London last Summer and got tired of taking public transport with our luggage and took a taxi from downtown to Heathrow. The cost was $150.

We are in our late 70s and now largely take group tours. You can find great tours from Gate 1 Travel or Road Scholar or Rick S. for $8,000, but it won't cover half of what you wish to see.

This tour of Italy costs less than $3000 per person and includes the big three, Venice, Florence and Rome as well as Pompeii.
https://www.gate1travel.com/tour/italy-tours-10dclaipom26.aspx

Here is a two week tour of France, about the same cost.

Yes, if you do it on your own, you could tour a bit cheaper. However, you hotels would not be as nice and your would need to do bargain type meals, like going to grocery stores. Still, you would need to use public transport a lot and that could eat away at the time you plan to tour.

If you do wish to do it on your own, buy a good tour book, determine WHAT you what to see and WHERE. TripAdvisor.com can assist with finding inexpensive lodgings and tips on cheaper restaurants. Also, once you get a plan, post on this forum for more advise.

Good Luck

Fun post. I'll throw some random things out but my biggest advice is to read, watch videos and pare down your list.
General:
Your budget is really good. You'll have some ability to splurge on some of your lodging choices.
-It's natural to try to include a lot of destinations, but each hotel change burns at least 1/2 day mucking about. Less is often more.

-You're smart to want to mix in days where you plan to wake late/soak up the vibe/recharge your batteries. A cafe table on a busy square is great entertainment.
-Pack light. I have come around to only taking a single 45L carryon travel backpack with a full zip. You only need a week's worth of clothes. Pick a color capsule so you can mix. Pick things that pack down and don't need ironing. Layer. Don't bring 3 pairs of shoes.
-I try to avoid AirBnBs, or at least avoid ones that are investment properties. These take housing stock out of a neighborhood, drive out locals, and ultimately change the complexion of the place you're visiting. I try to support small family hotels.

I know you're probably just kinda thinking about your choices of destinations but let's take a look at why you're not gonna have a problem filling your schedule...
Paris - 4+ days. There's a lot to see and it's your anniversary
Normandy - 3 days, depending on what your interests are. You kinda need a car or a guide with a car. We stayed and toured with These folks and it was awesome. https://www.normandy-battlefields.com/about-us. Are you adding a trip to Mont Saint Michel which adds another day (If so, I'd recommend overnighting there)
Loire - 3+ days+ depending on interests. It's a HUGE area and travel takes a while. Are you interested in Chateau or walled cities or wineries? I really liked basing in Amboise for my interests but a lot depends on what you want.
Annecy/Provence/SW - No experience but let's say you spend a minimum of 8 days plus 3 more hotel changes.
So just France you're at 18 days + 5 hotel changes (2.5 dead days) = 20.5 days just France. And you haven't killed an entire day flying or riding to Milan or Rome yet.

So plan on coming back to Europe. Don't try to do everything on this trip. Figure out what memories you want to make and mix in places that provide some contrast to each other.

Chris has given you wise advice.

Looks like a great starting point for planning, though my initial reaction is that you have a 5 week itinerary and a 2-1/2 or 3 week budget. Not too sure what to suggest to bridge the gap, but consider …

• Hotels will be more expensive in some locations than in others. Paris and the Riviera will be higher, for example. My guess is that Calabria will be less. Look to stay in more locations that are off the main tourist map, but do include one or two splurge places, perhaps Florence and Paris, or a beach town.
  
• Get a feel for hotel prices by looking at Expedia or Booking.com. See if booking directly with hotels is any cheaper.
• You will want at least some 2 star hotels to keep the price down; more charming 3 or 4 star hotels will cost more.
• Eating is another place to cut costs. More picnics. No Michelin starred restaurants. Cafe breakfasts of a roll & coffee, rather than larger breakfasts at the hotel might help you save a bit.
• Less is more. Trying to cover much of France plus Italy from top to bottom involves a fair bit of travel. If you go everywhere you have listed, there will be 10 travel days of roughly 2 to 4 to 6 hours, not including the time involved with hotel check-in and check-out and getting to/from hotels and train stations. So those 10 days are more like 1/2 days or 2/3 days of “being there.” That would be a lot of travel days for a 21 (or even 28) day trip.

Happy planning & travels.

Thank you for all the helpful and insightful info! We will review our highlights list and bring it down a bit.

Some good advice given above. I have been to all of the places you list, but certainly not on one trip. Here are my thoughts, and in particular an answer to your question “Is there a way to do 3 places in France and 3 in Italy?”. The short answer is yes, and the fact that you ask that question suggests that you realize your wish list is bigger than your allotted time or budget. Some things to consider in trimming down:
As it’s your first trip to Europe, it would be nice to see three of its best cities, Paris, Rome and Florence. However, I’d only include Florence if you want to see its artworks, such as in the Ufizzi and Accademia galleries. If so, be sure to book in advance. If art is not your thing, consider giving Florence a pass, in favour of a less crowded city like Verona, Bologna or Turin.

I spent five days in Tropea last May and loved it, but it is such an outlier geographically from the rest of your stops that I recommend cutting it. Also, I would suggest Annecy and Lake Como offer similar mountain/lake scenery, so I would not include both on a trip as short as yours. So, for your third stop in Italy I’d suggest spending several days in Tuscany, in either the Val d’Orcia or Chianti areas. You’ll need a car for this part, in order to visit several towns from your base in an agriturismo.
As for the French part of the trip, I’ve already indicated my preference for Paris and Annecy, so my pick for a third spot would be Provence, either in Aix en Provence or the Avignon/Arles area. Again, a car would be useful here. The Loire valley has lots of interesting chateaux worth seeing, but again, on a trip of this duration and breadth, I would give it a pass. Ditto for Normandy. Including the French Riviera will be very hard on your budget. You can get your Mediterranean fix in from your base in Provence.
So there’s my take on what to keep and what to cut in order to get a balance of scenery, culture, lake and sea views, and plenty of good food. It’s still going involve some long travel days, but it is certainly doable. Best of luck in your planning.

keep expenses down by careful hotel planning. I am amazed at hotel budgets by some on travel forums. So much higher than mine.

For something different ( and to amaze your friends ) in Italy stay at a monastery/convent ! In Florence, I recommend Casa per Ferie … Borgo Pinti. Great location. Can be booked directly or thru Monasterstays.com. My wife and I have stayed there twice.

Noting your "big lake and ocean people" comment, I see only Lake Como and the French Riviera that fit that requirement. There are, however, lakes and rivers throughout France and Italy (Arno in Florence, Tiber in Rome, Seine in Paris, etc.) I would still skip the Riviera and just not plan on spending any time near the ocean (except maybe going to Ostia from Rome for a day trip). If you go with most of the suggestions here, I wouldn't seek the oceans and lakes on this trip. You can still get some of that laid-back opportunity staying in Tuscany, Lake Como and Provence. (I remember kicking back in St. Remy de Provence, eating an ice c ream cone from a park bench and watching some of the "anciens" playing petanque on a balmy afternoon. I also remember sitting in the twilight of a cabanon in Aubagne, France listening to the cigales "singing", and during the day walking into the town center to buy provisions for dinner. Very laid back and peaceful.)

Everyone above has given good advice. There is much to think about and research and decide upon. I think most posters here relish the planning part of their trips. I hope you find enjoyment in it also!

Bonne chance!

Welcome to the forum!

I agree with the others about trimming your list a bit and will add…how sensitive to heat are you? Your profile doesn’t reveal your geographic area but since you are going May into June I might consider starting South and moving North. Paris can be hot in June but Italy will be hot in June.

I’m so happy you are planning this far ahead!

I think your budget is fine (as long as you don't expect luxury) and you should definitely plan the trip yourself and not take a tour. It's a lot of work but you have plenty of time. I suggest just spending the whole trip in just one country. I'd lean toward Italy because you could include Cinque Terre for ocean time. Trains are great for travelling but it's helpful to rent a car in Tuscany. Also check out the Dolomites for mountains. I use booking.com for researching hotels/apartments and usually book through them, but you can often get cheaper rates if you book directly with hotels. We spent 3 weeks in Italy and did not have time to go south of Pompeii.

That's a good point about weather, we are closer to you, Pam! Montana. Figured if I got super ahead on planning we could feel confident about our travel plans and can just it enjoy our time a bit more.

Booking stays at monasteries is super interesting, I checked that page out a little bit, thank you for that...

Looking forward to checking out the rest of the recommendations.

Thank you everyone!