Work on yourself bro. Have confidence, workout, sleep well, work well, dress well, don't be a dickhead simply wanting to take someone to bed, improve yourself. Girls will eventually notice and take interest in you. Reciprocate with the one you like and show her that you've taken an interest in her too.
But if she says no, gotta respect that and move on, there's still more opportunities out there. I wish you the best brother.