Sorry, guys. Your 'I'm new!' belongs in the Introductions and Departures section.
No, I'm not staff or anything, but that is where this belongs, just so you know next time.
To join a group hatch, you go to this section, called Group Hatchings, and then you click on the board that as created on this dates (you can see the date on the far left). Then you say, "May I please join your Group Hatch?" And if they say yes, which they probably will, you're in!