I joined just over a month ago, only started commenting recently, and just submitted my first post yesterday. There's no harm in waiting. There is definitely a "cool kid" or clique vibe going on at first but that was just my perception. Some of the members who have been around longer are more active, have more followers, and tend to get more exposure. They aren't inherently more interesting, they may just have more practice. For what it's worth, I feel much more welcome commenting here than I ever did on Reddit.