You're worrying too much. I had a friend who sounded exactly like you going into his freshman year. I was older and he kind of looked up to me like a big brother. He was scared shitless, never got laid in HS etc. etc. etc. He tears it up now, like absolutely destroys it.
Just focus on being social, making friends, and being a cool dude and you'll do fine.
Just focus on being social, making friends, and being a cool dude and you'll do fine.