Question about relationship with a Girl?

Hi, I'm a guy who just graduated from high school, who was rather reclusive over the years, but began opening up to some people. One of them is a girl who I talked to quite a bit (and honestly kind of like) and she said via Facebook message that we should keep in contact over the summer since we're going to the same college. Now that it's summer I don't see her, well, at all. I'm not saying I need help asking her out, but what should I do based on that statement. Do I just send her facebook messages every so often? I don't know. I'm really inept when it comes to social situations.