Hi, sorry i repply in english (or french f you need). Real Estate agent have to respect the french laws. Usually, it is better to go to famous agency, you will be sure they will recpect it (as century21, Orpi, Fnaim, LaForêt, Square habitat, Guy Hoquet etc...).
Before to sign any paper (promesse d'achat, compromis de vente), be sure you can cancel it if you need it (in case you don't get your credit from your bank). After that, you have 2 months to get your credit and sign the Acte d'achat with the notary.
My advise is to never have the same notary than the seller !
Also, the agency have to provide to you all legal informations before to sign the compromis (diagnostiques immobiliers, compte rendus de syndic, reglement de copropriété).
If they don't have it, take care...

参考になった