Does it mean something when a guy shakes his head and smiles?

You are making this too complicated. If he DIDNT like you you would know it because he would try to avoid you and certainly would not be friendly, or smile or anything. The issue of course is how MUCH he likes you and that is impossible to tell just by reading a brief write up. He might like you as a friend, or he might really LIKE you, but that is impossible to tell. For all you know, he might have his eye on some other girl around town, but still thinks you are cute, which is why he smiles and shakes his head, as in "what a cute but goofy girl" The number one thing you can do is not stress over it and give it time. If he likes you more than just a friend, it will become obvious in a couple of weeks or so. So relax, be friendly and dont rush things. Some of the best relationships start out as friendships.