France first time, 9 nights.

For a trip of this length, I would consider Paris and Nice. Nice is a good transportation hub, so you could take day trips from there.

You could also add some time to Paris and include day trips to places like Giverny, Versailles or Chartres.

Without knowing your interests and the time of year you are travelling it's hard to guess what would appeal to you. Rick has some suggestions here: https://www.ricksteves.com/europe/france/itinerary

If I were you I'd look at a few guidebooks (not just RS) and watch a few videos and look at a map of France. And I recommend your friend do the same. Then you can decide.

I'd stick with Paris and Nice. Four nights in Paris really gives you only three sightseeing days. You may well be a total zombie on your arrival day. Most of us struggle to stay awake by wandering around outdoors.

By the time you travel to Nice and get settled in, three nights would mean only two days there and a few hours. Although Nice is a good destination (with at least 6 worthwhile art museums, a daily market, and a picturesque historic district), most visitors want also to see some of the small coastal towns and hill villages. You need more nights to allow time for those excursions.

I admit to being a slow traveler, but for me nine nights wouldn't even be enough time for Paris and Nice.

So are you flying into Paris and departing out of Nice? Or do you have to backtrack to Paris for your homebound flight?

Nine nights goes by quickly. It may be wise to spend five in Paris and four in Nice and simply fly between the two. I flew that leg last September, it was 50 euro one way on Air France.

Lyon is one direction, Dijon another and Limoges still another direction. You will have to pick the one that appeals to you most. I liked Arles better than Avignon, but Avignon is more of a transportation hub. I haven't been to Marseille because friends told me it wasn't nice.

Train will be more expensive. It's possible to train direct from Paris to Lyon, from Lyon direct to Avignon and from Avignon to Nice. With your limited time, you really don't want a rental car because you won't have time for sights outside the immediate area of your stop.

I normally like to stay two nights to give me one full day for touring. If you leave Paris early, you can visit the Gallo-Roman ruins/Basilica in Lyon, walk the city center, get dinner in a Bouchon restaurant, then stay one night. Ideally you could leave early for Avignon, walk the center and head for Nice. It looks like the train to Nice is a longer ride (with a stop in Marseille). If you can't leave Avignon fairly early, it might be best to plan a night there.

If you are searching for trains using the SCNF sight, be sure to scroll through the day. Sometimes a direct train won't show in the time of day you search but runs at a different time. Direct trains can save a lot of time and hassle when you find the right one.

Given your timeframe I'd go with just Paris and Nice, most of that time in Paris. If you must add a third place, make it Lyon or Avignon, but that would be more rushed than I'd care for.

Seems like the only use for a car might be exploring around Nice. I'd do the intercity travel by fast train, or maybe air between Paris and Nice.

French trains (especially the TGV) are quite nice, but unless you really like train travel, it might be better to save time and fly from Paris to Nice. If you do like trains, I would recommend that you stop at Lyon, as another writer has suggested. Look at some sights in Lyon, then take the train to NIce Peter

I don't think flying from Paris to Nice would save a great deal of time. The train is 6 hours from city center to city center and avoids the hassles of two airports. That does depend to some degree on ones starting point; how close is the Paris hotel to the Gare de Lyon and the departure point for the chosen means of airport transportation?

For a trip of this length, I would consider Paris and Nice. Nice is a
good transportation hub, so you could take day trips from there.

I agree with Bob; this is what I would recommend too.

I advocate reversing the cycle. Fly into the south (Nice, Marseille --the latter is my choice), train back to Paris; fly home. This will allow you to get up at a decent hour of the morning for the return flight. Flying home from the south would probably require a European gateway connection, which means arising before the dawn. Be sure to plan through a multi-destination search function.