How do i become more confident and less socially awkward?

School starts in 3 days. And im scared as hell. Mostly for social reasons. To fit in you need to have Nike shoes. So I bought some. I didn't go all out and buy Jordans but I just bought purple kaishi runs this summer. and I also picked up white converse which is also pretty cool in my school. But I really have trouble fitting in last year. Last year I wore these really ugly shoes that were converse. It's not that they were ugly it's just that they were dirty. anyway I got made fun of a lot not just about shoes, about everything. So I was really self-conscious. I hung out with the wrong people. Fake friends. That didn't like me for me. They just made fun of me behind my back and front of me . I would go to the bathroom stall and cry. I would go home and cry. I was depressed i'd say. I felt ugly. They made fun of my features. Before that year i was confident. and now I'm really shy. In front of teachers, every time a teacher called on me my face turned red. I Am really self concious and shy. And socially ackward. How can i make friends with the right kind of people and not be so shy?