You can access by plane to the village of Lirac, it's only 35 minutes drive from the airport of Nîmes , 1 hour drive from the airport of Marseille or Montpellier. You can book your trip with traditional low-cost airlines, such as Easyjet and Ryanair.
You can also get there by train with the TGV from the station of Avignon (25 minutes drive). It takes roughly 2 hours to 3 hours to come from Paris to Avignon.
Then you can hire a car with companies such as National/Citer or Europcar.