You are in high school right? I would be more worried about vandalism than theft. If you do ride the bike, keep it low key. Don't show up in full cycling kit bragging about your great new bike. Let's face it, high school kids can be mean especially if you are not one of the "cool" kids.

If you can honestly say you are not worried about your classmates doing stupid stuff to your bike then I say go for it.

Paul