How should I start a convo with a girl I like on facebook?

[bananas]

We're both 19 and she was in the class below me in highschool. I see her working at walmart and I think she is the cutest girl ever and I can just picture us together forever. She is laid back, she is a hoodie-wearing, quiet, bookworm, kinda-girl. I know nothing about her besides she wears hoodies, she has rabbits as pets, she's single, and she goes to college here. I just sent her a friend request but she hasn't accepted it yet. I don't know what to do. If she accepts, should I talk to her? How can I get to know her without coming off random or/and creepy? I've never had a girlfriend or anything before, and I've never felt this way about a girl before. I go to walmart all the time now to see if she is there. Any advice? Conversation ideas would be helpful.