I really like this girl we get along great and we can talk for a long time easy and it seems like she likes me but she never seems to make the effort to start talking to me. I always have to reach out to her to get the conversation started and I don't mind but I worry that she is just being polite and just wants me to leave her alone.

It's very likely that she's just shy. Girl's also tend not to like making any move for fear of rejection. Do you make her laugh? Does she talk back to you? Does she smile? If so, I'm sure she doesn't want you to leave her alone, but it may not necessarily mean she's romantically interested... In all honesty, the only way to know is to ask!