If your expectations are not matched with this girl (and they are not), then you move on. That is what dating is all about...you go out, talk, get to one another, and if they seem to be a match and you like them, you continue and see if it blossoms into a relationship. You like her but she isn't a match over all, so there is no point in wasting your time or investing your feelings in someone like that.
On the bright side, you got over your insecurity hurdle and went out on a date. You can see now it isn't that difficult to do.