Avoid student loans as much as possible. They'll eat you up alive otherwise
No really, it's not that bad, but you should consider them only as some final outcome, or like... a desperate act or something.
Just study Japanese in school, and by yourself. Best way is to get a bunch of Japanese material and study by yourself. Most of the time, the Japanese you learn in schools is overly formal, and studying more on how to use your Japanese is probably important. Ehm, what you can also do is get a summer job. Work big time, save up the money and then travel to Japan and learn more there. I knew this dude who lived there for either half a year or one year - I think it was a year - and could basically talk, read, write and understand Japanese. The best way to learn a language is to constantly expose yourself to it. Watch tons of Japanese stuff, read lots of stuff, then, when you feel you can do it, try scouting out some Japanese dude to talk to
You live in the same city as I do, so I know there are lots of Japanese people around (not as many as Chinese though, I think).
Good luck! I myself am considering becoming an English teacher and live in Japan for a while because I really want to see what it's like there, and there are tons of places I want to see. Plus, I dig the asian chicks