First you need to find out what makes you shy, if it is talking to new people, start to chit chat your neighbors, people on the same bus or even people you do not know. You can stop them and say hi, I like your dress, or your hut. Then make a lot of friends to get used to being around people.
I dont think it's something you "overcome". I'm shy around people that I dont know. But I still have to talk to them when they say something of course. I've been this way my whole life. You either grow out of it. Or you tell yourself that it's just who you are and everyone else can just get over it. :)
just smile shyness is a good thing dont let no one tell you different your being put in a situation where its uncomfortable for you so when your ready to come whatever your ready dont let anyone pressure you too..