It's probably just the new kid syndrome. I moved every 6 months when I was younger so I went through it a lot. It's kind of scary trying to put yourself out there when you don't know anyone, and you feel like a total outsider. It's easy to just assume that everyone is unfriendly because you feel left out, but really, you can't stereotype people. Sure there are going to be a lot of assholes, but you can't let that stop you.
Your best bet is to just find something that you enjoy doing and try to relate to your peers through that. For me it was going to local punk shows. When I first got into high school, I didn't know anyone, but when I started going to shows every weekend I ended up with so many friends that I can't even name all of them. Of course, you might not find yourself a best friend, but it's a start. If you're not into the music scene there are plenty of other things you could do. Try out for a sports team, join a debate club, if you're interest in card games like YuGiOh, MTG, or Pokemon, you could start playing weekly at a nearby venue and see if you can meet people from your school there. Or better yet, explore the school and see if you can find people playing in the hallways. I went to 4-5 different high schools growing up and I ALWAYS found a spot where people gathered to play Magic at lunch.
Also, watch out for the whole peer pressure/bad influence thing. In my example of going to shows I met a lot of cool people that I could relate to but I also started getting into a lot of trouble...So even if you don't go into the same kind of environment that I did where drugs and alcohol are really prominent, just remember to be yourself, don't succumb to pressure just to fit in. Honestly, people will respect you way more if you don't try to act the part. I learned that the hard way when I started smoking cigarettes because I felt awkward being the only non smoker, and I had one guy full on tell me to my face that he thought I was the coolest guy there because I was the only one who didn't smoke, and that he lost his respect for me.
So yeah...hope that helps :)