Don't think to highly of other people, don't get me wrong, you don't want to think of people as less worthy then you, but a common feeling for shy people is that they're not as good as other people, which is total BS, yer just as good, probably better then some. So try and accept that, and try not think of other people as all that good, we're all just humans, and must of us can be pretty crappy deep down inside, so ye, good luck mate.
be yourself nothing bad really can happen they can't beat you up for being you. You kinda have to go through that faze where you start not caring what people say or think, nothing wrong with expressing yourself. Besides people like people that are more spunky and self confident
take a deep breath and keep a smile on ur face and try saying short word or just nid and shake ur head u will stop getting shy as u talk to more people slowly. im also shy but of talking on stage or in class Ow< good luck hun!!!!
Be happy in the skin your in!! Also know that you are MORE than the skin you're in! You are you! And to be outgoing, you have to find yourself! Give it time:) I also got into karate, it really helps with your confidence!:) hope I helped!:)