GYESWHO - You have a front brake and Jesus on your side? No worries.

ORIGINAL POSTER - get a front brake, or if you go no brakes and tell you parents to **** off, like you probably will being in jnr high school, get 45/18 gearing or something that is easy to slow down. I wouldn't stand a chance with my 46/13 with no brake, even if I only have a rear, which is not ideal, but fine.

Of course then you will spend all your time drifting and track standing, because you can't go fast! but hey you're in jnr high so that's what you might want to do anyway.

good luck mate! (i wish i got into fixed riding when I was your age!)