Answer: Fake it till you make it
Step-by-step explanation:
Sit down and think about who you want to be. Then, once you've decided, pretend to be that person as often as you can while you're in public, or even in private if that's more comfortable for you. Remember, nobody cares about what you're doing as much as you do. Eventually, after lots of practice, it won't be fake anymore. as time goes on, you'll find it much easier to talk to people and break out of your shyness.