Camping in France, Spain and Portugal is a pleasant experience. In all three countries there are two main kinds of campsite. There are the council run Municipal sites which are usually cheap but have all the basic facilities and many have swimming pools. Then you have the privately owned sites that have additional attractions. There is usually a shop, a cafe and a club with a bar and music for most of the night.
Traveling through France you will come across many picnic sites. Most of these allow you to stay overnight in your caravan or camper van and some don't mind tents.
In Spain the camp sites are not so frequent but when you find them they are of the same high standard. The laybys mostly have tables for you to picnic at and usually you are allowed to stay overnight.
The sites in Portugal are good, always lots of trees and water features but you have to look for them. You need to select a map that shows campsites.
Just a little advice about maps. If you have a map of Europe that was published for the English market you will be lost within a few miles of leaving the ferry. The English names of places on your map might be easer to say but they will not be found on the road signs. If you use a GPS you will need the appropriate software for the country you are traveling in.