Do girls like you if they smile and stare at you at the same time and they don't know you that good?

wel you don't know and I don't either. That she is smiling usually means that she see something in you that has evoked an emotional response. Maybe she thinks that you look funny, or she heard something about you, or that you look cute "to her". The only way to really know for sure is to walk up to her sometime and strike up a conversation with her and find out. start saying hi to her and see how she reacts. then sometime find something, anything to talk to her about - doesn't have to be clever, just usually in context, like the weather - if it is raining out and she is staring out the window, say "looks kinda gloomy out" or some such thing that is natural to you. Like if you were talking to one of your best friends. maybe you will find out!