Scared to talk to my beautiful crush? Is she interested? How do I do this?

OK, I'm 16 and a boy in high school. I've had a crush on this in my opinion gorgeous girl for a little bit over a year. She used to have a few friends and that was my excuse for me not to talk to her, cause I didn't want to interrupt her conversation and it would be embarrassing I thought. Yes, I am a coward.. but in my country people aren't very social, we aren't like in the States where you can just walk up to a random girl and compliment her, absolutely not. We are used to being quiet and that girls have one group, and boys another.

However, I've seen this girl, watching me before. Once when i didn't have a lecture and she did, but they had a break in the middle of it for a min or so, she turned and looked at me several times where I sat.

A few days ago when we had a lecture and finished, I saw her looking down, but I saw here eyes looking towards where I was, on my feet kind of. Might she be interested? Cause I'm sure as heck I am into her.

OH! Also, she doesn't seem to have any real friends anymore, I see her walking alone more and more and once I heard her say that she might seem shy in the beginning, but later on opens up. So I actually have no real excuse not to talk to her otherwise than that I'm a coward...

The thing is though, even if I would get the courage to go up to her and say something, what would it be? Like I said before, in my country we aren't very social and if I would say 'hi' to her just randomly, it would be way too obvious.