Firstly, of course, I'd be fully male.
Would you be 5'4, 6'0, or 7'0 ft. tall?
6' would be awesome. (I'm currently 5'5"
Would you be svelte, curvy, fat, or buff?
Buff, but not, you know, Arnold buff. That'd look a little weird on a teenager.
Delicate bone structure or larger, well-made bone structure?
Larger boned.
Big features or small features?
Medium.
Pretty much just a taller, buffer, male version of myself. xD