First Time Touring France

Gonz

My husband and I have booked a couple of sites in France (one near Geneva - La Combreire and 1 near Calais - Chateau du Gandspette). I was looking at the toll roads and wondered if the Electric Tag is worth it and how they work. Or is there a Pre Paid Travel
Card I could use? I did a little research but it says that some travel cards dont always work. Also is there a site i can find out how much the tolls will cost? I have found one but it only gives costs for cars and bikes, not towing a caravan.

Also, any other tips  on travel would be much appreciated. Or any tips on the sites we are visiting. Stressing already and I'm not going until August!

Thank you