Apply To Princeton University?

Hey, I am a high school junior who lives in a small town. I am really interested in plasma physics and desperately want to attend Princeton University. Unfortunately, being in a small town, I don’t have too many school options. What I mean by this is there are few classes like AP classes that stand out because my high school has little money.
I want to apply to Princeton Single Choice early action this October, and am wondering what else I can do to boost my application. Also, I was wondering who I should contact at the University to help my chances.
Right now I have a 3.907 GPA (unweighted), an ACT score of 27 (which I will definitely be boosting next time)
I also am the president of our class for two years now, the vice president of my school’s National Honor Society chapter, a member of Key Club, the founder of the school store, and co-founder of a religious group at school. Along with this, I play the trumpet and am involved with the jazz band and city band. I have gone on a mission trip to Honduras and will be returning again before the application time. I have attended a HOBY seminar and will be headed back there again as well.
Thanks!