Question about talking to a girl?

So I really like my friend but I'm not sure if she fills the same way. And she does things that make me think she does like she ask me to work on her car or she will ask me if I wanna go see a movie and for a while now thats what we seem to do alot is go to movies, but she doesn't like me paying or buying her stuff (food, car parts). And when we text eachother its just about random stuff. Like she tell me how she hates her Job or how someone in traffic annoyed her she is kinda funny. But I really have no idea on how girls work or what to say because I've been burned really bad. If someone were to put a gun to my head and say ask her out or else I would fail because I'm so afraid of rejection and more importenyly leave if I'm wrong what will happen, will she stop talking to me. And another thing, if she does like what should I say, like what should I text to kinda letting her know I'm more serious because we have never talked about anything serious or personal at all.