How Do I talk to this girl I like
so I like this girl and i am a junior in High-school and i know she likes me back from body language signs when i have talked to her in class. She will do the following when i am around or talking to her in class. She will tend to pull gently on her hair, cross her legs with feet pointing towards me, try to get closer when i am sitting by her, asks me for help on things she might not actually need help on because she is acing the class, when we talk she gives no eye contact i think because of shyness or nervousness but smiles and listens intentively. Problem is though i cannot talk to her freely. Once class is done we will pack up our stuff and head downstairs to the lunchroom but i want to talk to her during the walk but i cannot find a topic to talk about because i think it would be awfully awkward for her and i because we don't really know each other all that well other than each others names.