My problem has been:
a) I've come from bird site which I used as a curated source of journalism & information so I was largely passive; I had nothing to say.
b) I'm essentially introverted and shy; I tend not to say much, especially in crowds.
c) I don't really understand the point of social media; I don't have a sense of self-importance to believe that my opinion is worth expressing publicly.
Consider this a friendly, local pub. Make yourself at home, bring your friends, have a good time! Meet new people, have a laugh, enjoy the ambience, and the Oxford commas.