Be natural. You seem to be worrying too much. First impressions ARE important, so I suppose it's most important to be natural and not act like something you're not. Maybe try to talk to girls more... you know, casually, don't think too much about trying to get a date with them, just talk. It'll probably help you become more comfortable around girls. It'll help you to be more natural.
If you are just you, and don't deliberate about what you're going to say (what i mean is, no unnatural conversation), you should find somebody. Fear of rejection is hard, but once you start debating with yourself whether or not you should ask some girl out, the time should come when you feel strongly enough to just gather your courage and ask. And once that happens, you gotta be ready for anything. Just think, what's worse: asking and getting rejected (but having a chance), or not asking and never have any chance?
If a dream comes true... then is it still a dream?