For someone in high school, I know the only thing on your mind is college, but you need to be thinking about what you are going to be doing after college and then think how you will get there and your actual chances of making it there and that will answer questions like "what college should I go to?" and "what major should I be?
No matter what college you go to you should be able to double major, major and minor, or at least take electives in a certain area.
I would suggest going to the best school you can get into and focus on getting a degree in an area where you can get a decent job (business, engineering, computer science, etc.) and then for your electives just take a shit ton of film classes and see if you can minor or double major in film. And spend your spare time working on film stuff.
That way if you find out film is what you're really interested in, you'll have enough time to do it, but you'll still be getting a degree that will provide you with a decent job so you can support your film hobby after you graduate.
It seems like even if you go to a top film school (USC, NYU, etc) the job options are extremely limited and pay shit. You're most likely not going to be doing anything 'creative' anyway so it'll pretty much be a regular job that happens to be with the production of film.
Good bet would be to try to tie together your career qualifications with your interests, like marketing with film and then trying for a job at an ad agency. I know a girl whose doing film school undergrad then going to law school so she can be an entertainment lawyer.