The way to go about getting the attention you want is to realize you have a pair of balls and you don't tuck them behind your legs.
so...
when you walk into your class and if you're sat next to someone - introduce your self and shake his or her hand...this shows that you are friendly and confident. strike up a conversation with someone at the lockers - you'll get attention.
Get the attention - you have a voice, speak!
If a guy gives you shit - say something cocky for example if someone says "whos this bitch?" you say "describe me to your mother, im pretty sure she'll remember me"
Be sociable - smile. No one likes a guy who looks like he has a face like a smacked arse.
DO NOT COME ACROSS AS NEGATIVE!! i did that for a 5 years straight, not once did it help me in any shape or form in fact it destroyed my confidence.
And as for your fashion - research some mens fashion - standout from the crowd, in a good way. chicks can see what matches and what doesn't - peacocking theory. and where something that you feel comfortable and feel good in. For casual wear i like to wear a red checkered shirt, dark grey jogger jeans and ankle high military boots. Where some nice aftershave too - have a clean smell.
And as for people around you - ask where a certain room is, whats this high school got to offer, where do you hang out at lunch etc - connect with people dont push them away..not yet anyway....walk past every hot chick and either say "hi" or "nice top" and strike something up from there - talk about your self, engage with her.
Body language -walk as if you feel good about yourself - it shows confidence. make eye contact with people, make hand gestures when you talk with people - dont keep your hands at your side or in your pockets. To show that your're an alpha male - stand in an alpha male way...an alpha male will put his hands on hips to make himself look bigger and look as if he needs room around him - it works for me, when a guy gives you shit, stand like an alpha male, stick your chest out and raise your voice - dont bellow, unless the other guy wants to fight and you can shout at him telling him to back off etc.