I think you will find, VT, as you meet the denizens of this forum face to face (and I hope you will meet many), that most of these folks are very much as they appear to be in the threads. Because this is primarily an acoustic music site, most of these people are fun-loving, and not very shy. Some of us are fun-loving nearly to a fault (Peace Cabin all night jam, anyone?), and we have enjoyed the repartee for so long that some of the stuff may seem like in-jokes from the "Mudcat Inner-circle". I reckon we just can't help that. It's the same thing you'll see if you join in with any long-running jam session. There's often a familiarity among the usual participants that may seem intimidating at first. But when they start giving you a hard time with a smile, you know you're breaking the ice.
I would not worry too much about rules. These people don't grade hard. Beginners are always welcome.