Here are two links. Start with the first, then study the second carefully.
http://www.rustica.fr/questions-jardinage/comment-vendre-legumes-son-potager,9993.html
http://www.terresdeurope.net/en/being-farmer-farming-france-agriculture-farmers.asp
Farming is a tightly regulated activity in France - farmers’ interests are very well protected, and that makes it a bit of a closed shop. If you make money from the land, you are potentially subject to the MSA which involves paying cotisations, and depending on the scale of your activity you may or may not get social cover in return. Running a smallholding in France is not going to be like running a smallholding in Lancashire but with more sunshine, there is far far more red tape involved.