Whats Junior High Like? I'm Scared...?

I'm going into junior high this year, and I'm really nervous. First, I heard that lots of peoples grades drop in junior high. I'm in the advanced cles, but I have trouble with organization and I'm bad at turning in homework on time. Also, lockers? Are they hard to keep organized? AND I don't have much money for clothes, so I just went to a bunch of resale stores. I'm not allowed to wear makeup and earrings and stuff, do people care a lot about that? And I'm very shy, so how do I make friends? Any advice would be really really helpful. Thanks :D.