What should I do about this girl who likes me?

I am a highschool student and people look at me as an innocent little kid. But there is this girl, my classmate in my first year of highschool, last year. She is cute, etc. and being sought-after..a bit. I always listen to her problems and helped her. After I knew her crush, I was a bit jealous, and found out i had a crush on her..a bit. :P In my second year of highschool, I only found out that she already had a crush on me, said some of her friends. She has done many things showing that she liked me but i think she doesn’t like it too much that i’ll know that she has a crush on me. I don’t want to get close to her too much…especially when the time comes that i might court her or something. i don’t want that. it’s beyond what i want my life to be or how my life would run. My friends told me that I am really stupid. They think that i don’t know anything about girls, love…etc.

One thing, if i am able to court her and she accepts me, i might end up leaving her someday and she will be hurt or i don’t want any “certification” that she is my girlfriend and i must care for her, adding up to my responsibilities.

So, what should i do?