Why cant i just go up to a girl and tell her i like her without being in a weird situation?

ive liked this girl for 2 yrs, 2 yrs ago it was just lust i suppose and i though that she was really pretty( she was only in my lunch cl), last year she was in my spanish cl and i found out that she was really smart( in all honors cles) , a talented singer, a great dancer, and very popular, but despite being popular, she never showed off, i never saw her mocking someone, and she was just a quiet but nice girl... this year i only see her when in the hallways sometimes when im going to another cl, but i really like her and just wanna be friends with her.. she seems like such a great person.. how can i just tell her that? or how can i get to be friends with her?