Did you ever feel like you don't fit in?

I'm about to go on a second date with this girl. I thought I could have been a better date during our first date but she invites me to be with her alot so I don't think too much of it. So, I was on her facebook looking at some of her pictures and now I'm a little intimidated. She seems to be quite popular, and I don't really compare to some of the friends. I'm not as big, as rugged, as ually appealing etc. What if the friends don't accept me as her bf and tell her she can do better? I do have some nerdy tendencies. She invited me to an event where alot of her friends might be present, that's why I bring it up.