first, do a simple campaign don't turn against anybody. your dress get a cute prom dress with some heals that will say i'm what it is. third your date maybe get a boy that is really close to you or something. makeup something not to bright, but at least let it match your dress color.
Dress- You can wear whatever you want pretty much. But I wouldn't go too slutty because then the girls won't vote for you.
Makeup- Pink tones make you seem nice, friendly, and bubbly, but only if this will look okay with your dress.
Date- This won't really matter. Go with who you like.
Campaining- BRING CUPCAKES! Or just be nice to everyone ;-)