Absolutely. You can do all types of activism including simple street art and pamphleteering by visiting sacredscribble.com. Also attend protest marches such as the March To Close All Slaughterhouses where you will be very welcome and in good company of other vegans. Well done on your commitment!
I can’t give you much advice, because I myself have the same problem. However, the simplest way to get involved is by creating a website/youtube channel/IG account to spread awareness?
I’m a very shy person too. What I did was to start creating art to show how I felt about animal rights and pollution. That’s a good way to start a conversation! Then I realise that even if I couldn’t talk to many people at the same time because of my shyness, I could do well by talking one-to-one with my friends and family. Then I extended the conversation to "people I know". With time it became easier and easier to speak out my mind. I know this doesn’t sound like big activism, but I’ve found that you can gently change your surroundings by doing this kind of micro-activism. You’ll get more confident with time and practice!
Cubes of truth would be good because you’re not directly talking to people, just standing there holding a screen