The first thing you could do is to try and identify what makes you afraid/ shy to do something. Are you shy to start conversations with big groups? If so, start with the less intimidating ones
I used to be really shy too. I would only talk to my group of friends. However, I joined Girl Guides and was given the task to lead them. No choice, I had to project my voice to a group of 60 and that’s when I realised, I could do it. Sometimes, it takes a dive to break this barrier of shyness. I know it’s hard, but try not to assume what others are thinking of you!
You could start off by initiating conversations with the people around you. If you just entered a new class, find someone who is alone and strike a conversation with them! They are most likely looking for someone to talk to :) ice breakers could be “how did you end up here?” “What’s your name?”. The conversation should flow between the both of you. If it’s awkward (which could happen to ANYONE), just excuse yourself to the toilet