Southern France

This is where my initial planning stands.

6 days Nice
Monaco/Monte Carlo. 21 minutes by train
San Remo: 1 hr 11 minutes by train
Beaulieu Sur Mer: 10 minutes by train
EZE: 14 minutes by train

4 days Vallouris
Antibes. 6 minutes by train
St Tropez by boat (September)
Cannes 5 minutes by train

3 days St. Paul De Vence ( Car-but stay outside of town)
Luberon HillTowns (Cote de Rhône)
Grasse

3 nights Marseille
Heyeres: 1 stop by train
Aix: 1 stop by train

4 nights Avignon or Uzes
Arles
Nime,
roussillon,
gordes,
uzes

I haven’t been yet, we are going mid May to Nice…
But I’ve done a lot of research so I just wanted to tell you the train to Eze results in a long hike up to the town. IT’s recommended to take the bus, or easiest - take an Uber. That’s our plan.

We have an airbnb in Nice for a week that seems central to promenade, old town and train station.

In Nice, taking a food tour, which takes us through the farmers market.

Day trips planned to:
Monaco/ Menton same day
Eze (via Uber)
St. Paul De Vence/Vence (via bus)
Antibes and Provençal market
Villefranche, and seeing Villa Ephrussi

there are antique and artisan markets in Nice we will check out.

There is also a transportation pass you can buy €50 for 7 days covers tram/trains and buses on the Côte d’Azur. Shorter timeframes also available.

Thank you. Enjoy your trip

I don't quite understand this:

3 days St. Paul De Vence ( Car-but stay outside of town)
Luberon HillTowns (Cote de Rhône)
Grasse

The Luberon valley is where Gordes/Roussillon is located, at the end of you itinerary. You can add some time there and explore the southern Rhone Region.

You could simply extend your stay in Vallauris (a more unusual choice). You can also drive further into the Nice countryside, by hitting St. Paul de Vence, Vence, Tourettes-sur-Loup and Gordes. Grasse is OK, but it is best combined with other destinations like Mougins and Valbonne. Biot is another nice destination.

Hyeres is a nice town but a bit stretched out. It is easier to reach it via car. You could consider a one-way rental at the end of your journey. I'm not certain what you are planning to do in Marseille but one night may not be enough. But don't try to day trip to/from the city by car.

First, consider taking the bus to Monaco instead of the train. You'll have views, vs none on the train. If you plan to go into the casino, other than just the lobby and slot machines, you must pay, I think 25 euros and have your passport.

Thank you for your suggestions/advice. I have to pay closer attention to maps and modes of transportation.

From Marseilles to Aix you can take a local (TER) train that makes several stops, takes 46 minutes, doesn't require a reservation, and drops you at a central station (Aix Centre). Or you can take an express (TGV) that makes no stops, takes 11 minutes, requires a reservation, and drops you a few kilometers outside of Aix itself (Aix TGV), requiring a bus or taxi to get into town. I'd go with the local for convenience and price, even though it takes a little longer.

Actually, from Marseille to Aix, while the train is perfectly valid, I prefer the bus (50 from Gare Saint Charles). More frequent (every 5-15 minutes for line 50), slightly cheaper, slightly faster (peak traffic flow is Aix -> Marseille in the AM and back in the PM, so rush hours do not affect day trips from Marseille to Aix).