How wonderful that you found this "class"!
There's absolutely nothing to do to join up--because it's not a 'class' in the usual sense of the word. It's just a topic a week (usually a literary term or device), with a brief explanation and examples from me, and then discussion and more examples from anyone on the boards who cares to submit.
I ran the classes for about a year, during which time the message boards melted down and about half of them disappeared forever. However, you can still access the more recent threads, and you can still input your own thoughts and/or examples.
I plan to start up again in the fall, with a slightly different focus (I haven't quite decided what that will be, yet). I hope you'll jump right in at that point! In the meantime, feel free to check out some of last year's sessions to see what they're like.
Nice to meet you!