Don’t try so hard. Try to be casual and don’t make it into a do or die situation. The more you can do this the more you’ll just be yourself, which is what you want to be anyway. Ask them questions about what you think they’re interested in, listen to their answers, and try to relate to them by your response. If you can’t think of what to say, don’t say anything. Let them talk and look for openings to relate to them. Make up a list of subjects that you could talk about, think about how you feel about these subjects, and bring them up with girls when it’s appropriate. Remember girls are just people like you.