It's similar. Pupils are evaluated on their last 2 years of high school. The bacalaureat (equivalent of the A level) doesn't factor in because it comes too late (July-August, after it's already decided where you will be going).

This can be very selective or not at all depending on where you're going, there are totally different tracks so it really can't be discussed in general (Law, Medicine, Engineering, Business, Art, trades, etc...). All are basically free, except business schools that are always private and super expensive.

I think that's the main difference between the US, US always have gigantic college of 30000 students that cover everything, whereas France is rather fragmented.