Well, regarding the note, are you sure that she received it?
It does sound as if she likes you, so why not suggest doing something together ~ in a group, perhaps?
Do a group of you ever go swimming, or bowling, or to the cinema or a cafe or anything like that?
If so, you could ask her to join you.
If not, you could try to arrange something with some friends, and include her.
If you tend to discuss your schoolwork, maybe you could suggest going to the library to study together.
Welcome to the forum & good luck!
