While you're in St Jeannet, go and taste some wine at the Lango Mai winery. They are friends of mine. Taste is a bit surprising, but you will experience wine as it was made centuries ago. In Carcassonne, of course, you will visit La Cite. I spent my teenage years in Carcassonne, I have magic memories of my first love within these 13th century walls. In Britanny, you can visit Port-Louis, my village. Our house was built in 1636, back from when the little city was trading with Pondihery in India. Lorient, the city on the other side of the bay was flattened during WW2, but our little village made it through largely unharmed. Near there you can visit le Golfe du Morbihan, Quiberon, Carnac and its menhirs alignments dating back to keltic times. Next to there la Cote Sauvage is also a beautiful place.
If you drive across France a good trick is to buy a Michelin map, and follow roads underlined in green, away from the highways. That's the best way to discover France. Don't miss le Pays de Cocagne, in the Castelnaudary area, on your way out of Carcassonne. And have a nice cassoulet in Castelnaudary.