You know, it's strange that girls seem to think that boys are so positive and confident. For some, I don't think it even enters their heads that boys might be nervous, too.
My advice is to forget about flirting and concentrate on just being friendly and interested in what she has to say ~ also to comment on your own interests, but without hogging the conversation.
What are her hobbies?
What music does she like?
What films does she go to see?
What subjects does she enjoy studying?
Does she like to travel ~ have you visited the same places?
Think about your own hobbies, favourite music and films. Have some ready-made thoughts in your head on these subjects, so that you won't worry about not being able to continue a conversation.
Once conversation flows naturally between you, you can suggest listening to music together, or going to the cinema together, to see a film you both like the sound of ~ even if you choose to go in a group at first.
"The secret of success is constancy to purpose" - Benjamin Disraeli.