I really like this girl what should i do. ?

I am in the 10 grade. I like this really cool pretty girl. She looks at me often and says hi to me and asks me how i am doing. Whenever she says hi to me she always says my full name. We have the same homeroom and whenever i get there she is standing outside the clroom.when i walk in she then walks in and sits beside me. She looks at me often but i dont look at her because am nervous. In another cl she sits behind me and often plays with my desk. I want to know if you think she likes me and if so how should i get het attention.