I want something for my 14th birthday that you really do dress crazily because thats what we like, but i think cannot an appropriate theme. Also i dont want something stupid when you see that you may think “well thats gay”

Ok, so this is some theme issues that I can choose:

I like ‘70 to ‘80 theme. We did that for a new year theme a while ago (me and my cousins) and it was really fun. Thanks!
Or what about a ‘80 Punker theme? Wear a variety of bright bold jewelry and do not forget legwarmers.
Do a 80 themes that way they can where the old hair styles in the fall of the shoulder, shirts for the girls, and the boys can get crazy hair cuts and they cand break dance or do what ever. 

Hawaiian theme, people like it. Make some fake grass skirts for the girls, including a coconut bikini top will be fun. It also allows the boys to wear tropical shirts. Much of pineapple and melon dessert will cool.

If you want to dress up a casino night. Anyone can wear semi formal kinda stuff and can be a blackjack table.

A fake Halloween theme is cool to have your own birthday summer haloween

I can also try jingle jungle in the room of ur party leaves and flowers decorate with plastic ones and give a green fountain wataer And play hiphop muzic.

Movie theme, everyone can be as a character from a movie.
Or what if you tell each person to dress up as someone from their favorite show or video game, etc. At the party and then everyone has to try to find out what game show of them.