Not sure how old you are - but to go to a public high school you need to be living in the district w

Not sure how old you are - but to go to a public high school you need to be living in the district with the school. that means joining a program that would find you a family to live with. If you don;t live in the district you can't go to the school (education is all local in the US). If you expect this to be an educational international flight tickets experience rather than a cultural one you will need to find a very high quality district (they vary tremendously from one to another). As for a private school you could do that if it's a residential school - but it will be VERY costly. (Good day schools cost about $20,000 per year.) Also US high schools take only students who have not graduated or have not reached 19 years of age (we usually graduate at 17 or 18 - depending on month of birth, at 16 if in an accelerated class.)
If you have graduated from high school in France - then you should be applying to colleges in the US - NOT high schools. And yes, it;s too late to do so for Sept. In fact the applications for Jan or Feb are closing now. And you would have to secure the appropriate application international flight tickets forms, find a way to take SATs (college entry tests), gather recommendations, write essays, fill out form and pay application fees. Colleges are even more expensive - except for some state universities international flight tickets - which charge international flight tickets more to out of state students - although many colleges do look to provide financial incentive to exUS applicants that are well-qualified.