You have heard of the old expression, To thine own self be true!  Be yourself, don't try to be someone you think she would like.  Just approach her and strike up a conversation and say I've noticed you are interested in ??  Whatever you have seen her do and classes she attends, don't be afraid, just do it.  You will feel more comfortable in talking to different people the more you do it and think of it this way.  It's a learning experience.  You can find out about many things and also learn things from people as they can learn from you.  You also have a lot to give even if you don't know it.  Just Smile and be yourself.