Stay true to yourself.
Keep your head down low, and don't get yourself involved in anything unless you're 100% committed in doing so. Quite honestly, high school's gonna be the time in your young life when you feel the most pressure to do things socially, but truth is when you're like me and you look back 10 years from now you'll realize half that shit don't matter. Have a clear envisionment of what you wanna do and go for it, get a part time job to support yourself, and focus only on you, don't worry about what anybody else is doing. Oh, and don't worry about things like girls or parties, instincts will get you all the external luxuries you want and none of the internal ones, so whatever you think you should do in that case - do the opposite.
People all want to be popular, but what people forget is how to build characteristics that make people popular. You do all these things I say, and you'll see how quickly people draw to you.