If you think she likes you, then you're halfway there.
Just relax and be yourself. Don't forget to breathe!
Keep it light and positive. Ask her about her. What's she up to, isn't it beautiful out today, anything.
Don't take yourself or her too seriously. Make fun of her or yourself. Have fun with her!
If she's receptive, then flirt a little bit, but not too much. Don't be too eager; you have plenty of time to get to know her better. Just establish that talking with you is a fun thing for her.
Don't forget to listen to her answers to your questions, and if there's a way to reference them later in the conversation, do that. Especially if you can do it in a funny way.
Don't let her be the one who has to end the conversation; leave her wanting more. Tell her you gotta go because of... It shows you have a life. But don't make something up. Lies are a dead end road.
Touch her arm every now and then while you are speaking. But be very casual about it, and don't grope her! Keep your eyes off her boobs (for now). Women hate that.