Municipal sites are good, usually with high standard facilities at a good price. All areas will have municipal campsites. Do not stay overnight in the peage rest stops. We were burgled there, not a pleasant experience. France is huge with an ever changing scenery, do you have any idea what you want to see or where to go, or even how long you have for your holidays?
I know it will be manic but we have bitten the bullet and bankrupted ourselves bought a shiny new motorhome. Would live to hear motorhomes views on France with kids. Best ferry/train for motorhome placed to stay etc. any help much appreciated. TA x