Hi, and welcome to the forum.

I take it you are Italian (which is handy, as you won't have to worry about all that visa stuff!). But I don't think you are eligible for RMI if you have been self employed before coming to France. Under some circumstances, if you are receiving unemployment in Italy before you move, you can continue to receive benefits for the first three months or so in France. The French don't offer much (or any) benefits for business owners. You may want to check the Assedic website https://www.assedic.fr/assedic/assedic.portal for more information.

They have just announced new rules coming into effect soon that will reduce your ability to turn down jobs proposed by ANPE - don't have a source for that, but there was something on television here about it last week. IIRC, they are saying that after you turn down two jobs offered, your benefits will be suspended. But I don't know when that goes into effect or if it's still just a proposal.

For French classes, you'll have to check with the local mairie (town hall) where you wind up living. Since you won't have to sign one of those contracts of integration, you won't be eligible for the State classes aimed at immigrants, but some towns run French classes. There are also some volunteer groups that offer French classes for foreigners at low cost.

You might also want to take a look at the europa.eu website, which is the portal site for the EU. There is quite a bit of information about working in various countries - and the information is available in nearly all the languages of the EU.
Cheers,
Bev