College / Filmmaking question

Hello! 

I am 16 years old and currently a Junior in High School. I've wanted to have a part in making movies since I was young and because of that I'm planning on going to college to major in Theater. At the specific college I'm planning on going to, you can take a bunch of different classes under 'Theater', like Directing, Movie & Television Acting, Musical Theater, and Design/Technical Theater (so, the behind the scene stuff that isn't directing). I want to be successful in this field, but I have no previous experience and doubt I'll be able to gain much in the small amount of time I have before I graduate next school year. What should I do?

My Plan B has always been to become a teacher, preferably US History. Should I dual-major in Theater and Education then minor in History? Is that too much? I've always been an honors student, but I have some trouble with organization.

I've always been told I'm a good writer. Should I try to become a writer for Film instead? I don't know what actual role I want in the field yet—I just know I want to be a part of the magic, y'know? I'd probably rather be a director (I know, a lot of work) or an actress but, like I said, I have no experience with anything and frankly don't think I'd be good as an actress.

If anybody has any thoughts/advice about ANYTHING, that'd be helpful. Thanks!