Places to visit
Minerve.. Small historical old city, Plus Beau Village, unesco. In gorge up on hilltop. Pretty, takes few hours to walk around it. Takes 1 1/2 hours to get there
Plage before Sete, return to beach 🙂 Trois Dingues
Carcassone, maybe on same day as Minerve if leave early. See castle, not city centre. Walk through castle, fee. Drive to Cite ( not centreville)
Narbonne. Bigger centre, historic. Has canal running through middle of it. Park at Les Halles parking lot and then will be right by canal and shops and city centre from one parking lot.
Montpellier, big square in centre, lots of shopping. Park at Comedie parking lot and will be right in centre square.
Nimes, historic. 1 and 1/2 hour away. Could do Nimes and Montpellier in same day.
Arles. Could do Nimes and Arles same day! Pont du Gard. north of Nimes. Bridge and Nimes same day. :). old roman aqueduct.  
Avignon. hour and half away. pretty much a whole day by itself. Little train may be available to take you around city. May not be still operating this time of year?