You could join a youth club with your friends. Ask your friends if they will bring their friends, male AND female, so you can mingle and make new friends. That way, you'll be with your friends, but around NEW friends too so you won't feel as shy then if you were on your own.
Or, you could go out shopping with your friends and ask them to invite other people too. Either way, I think that you should involve your friends so you won't be alone.
Or, you could totally just go online and get peoples e-mail addresses and e-mail them. But you'd have to be very careful if you were going to do that because the internet is quite a dangerous place to be nowadays.
Good luck (: x