I know it’s hard to overcome being shy. If someone is talking about something you know about don’t be afraid to comment. I know a place you can practice is when you are in the grocery story. Standing in a long line kinda of make small talk with the person behind you, if they look friendly, you don’t have to see them again if you become embarrassed. Speak to people more when you are out. Try to go to a social function with a friend and mingle. You can’t continue to stand in a corner if you want to come out of your shell.