You have several ways to buy food in France :
- go for small stores like butcher and baker. Those usually offer the best quality but the price could be expensive.
- go to the supermarket. You have small, medium and hypermarket. The bigger the supermarket is, the more choice you'll have. Supermarket offer a selection of local products and national brand products. Pricing is usually the cheapest and quality can vary. You'll also find organic (bio) shopd but price are really expensive.
- go to the fresh market that you'll find twice a week in most of the towns. You'll find there freshest products usually coming directly from the farm.
Few advices to eat good food :
- buy local products rather than products coming from the other side of the earth. You'll find a lot of fruits coming from a lot of foreign countries. They have traveled a lot so I let it to you to guess what they are made of to be able to absorb the travel delay...
- ask the locals. People will be delighted to give you directions to the best shop.
- ask the store staff, they will also give you ideas to discover seasonnal good products.
- check the shops where is a queue up to the exit, this is usually a good sign.
- check for awards. Best shops received awards and are usually very proud to highlight those. Shops without awards aren't necessary bad but shops that received awards are definitely good.
You'll find some reviews on Google local business listing and also the pages jaunes but usually not a lot. So rather ask locals. You will see them walking with their little caddy in the street in the morning.