Depending on the state you're in, etc., you might be able to major in Stage Management, take some theater ed. courses to satisfy theatre elective requirements, and still get a teaching certification-- you generally don't need to major in XYZ education to get a certificate. (At least in Texas, where I am, I know this is the case.)
I second what everyone else said, though. Take at least this first year to just get into the whole college thing, get your basics out of the way, etc. You're already way ahead of most college freshmen-- as far as I can tell most don't even know what their major's going to be.