Be bold. Be brave. Don’t hang back. Don’t let shyness or indecision take hold. Here’s a thing. When you’re feeling a certain way, and it’s preventing you from moving forward, simply acknowledge the feeling and speculate on its origin. “I’m feeling a strong urge to (get involved, join in, help, whatever it is) but I’m (not sure how, unfamiliar, a little scared, whatever).” Anyone worth their salt will appreciate your intent and help guide you in to what you both want.
The longer you agonize, the harder it will be. Just say okay and let the happening wash over you. You are among friends. You are supported and loved.