If you're too shy you can start singing by yourself at home. I love singing and do it at home all the time. It brings me a lot of enjoyment. I think making yourself happy is probably the most important thing.
You can also try to just make more friends, even casual ones are fine. Include married people, they love to introduce possible matches to their single friends. If we know you in real life there's totally chance for friendship. I sing, too and my hub plays various instruments. Lots of IT people in our families. Unfortunately all our younger sisters are married now, but there are still lots of cousins. You're still very young. Perfect age to go and have all sorts of fun, or work on improving yourself. No need to panic about not being in a relationship yet.
If you're ever not sure if a girl is interested in you (happened to me a lot, I was so oblivious), try something small, like go to the food court and have lunch together, offer to walk her to bus stop / train station at night, have a coffee and chat a bit, borrow something from her and return promptly, study together before exams, give her a ride, help her move some furniture (but she better buy you a big pizza)...etc. Basically just ordinary stuff friends do. Usually you'll find out if she's really interested or not after spending a bit more time with her as friends. These won't scare her off, and won't embarrass you if she's not interested. It won't hurt to have another friend anyway. You never know she might have just the girlfriend who might suit you better.