Since the company is based in France, the short answer is that you should expect meals to be covered together with the hotel and travel expenses. It wouldn't be odd at all to ask about that. Some of the meals might be provided as part of the onboarding or possibly in the cantine (if there is one, which is not generally the case at startups), otherwise you should be able to expense them.
Incidentally, since the tax office (technically: Urssaf) allows paying up to €19.40 each for lunch and dinner with minimal formalities and no taxes, many employers will simply offer to pay that as a matter of course, no matter how much you actually spent. If you want more, you need expense the meal following whatever process your employer put in place and their accounting department will require receipts. These rules do not necessarily apply to you as you presumably do not have a French work contract but this should give you an idea of what travel policies tend to be like in France.
If you were based in France, you would not be entitled to time off or any compensation for the fact that you are not able to go back home every night so unless there is a specific legal obligation to do so (e.g. through a collective bargaining agreement), I wouldn't expect your employer to give you anything beyond transportation, meals, and lodging.