Wanting to get over social anxiety isn't a good enough reason to try to become a professional actor.
However, taking acting classes at a good school for a year or two would probably help you become more outgoing and confident.
If, after that, and having performed in public with a community theatre for a couple of years you truly love acting and regularly win good roles, maybe you might consider trying it as a career.
In the USA, you don't have to go to college but in the UK, you do - or rather a drama school.
But either way, it usually takes about seven years of training to get to be good enough to be signed by an agent and get some auditions.
It's a long, difficult process!