Your 2013 Rubicon doesn't need ANYTHING added to it at this point. You will be perfectly fine wheeling it on open runs with the club for quite a while before you need to consider adding equipment or making modifications. It already has good tires and good tow points - those are the two key things to start wheeling. It also has a lot of things that most Jeep owners need to add after the fact - lockers front and rear, 4:1 tranfer case, sway bar disconnect, fuel tank skid plate, rock rails, and Dana 44 axles front and rear.
Go out on any open runs that you see pop up - you'll learn a lot. Don't worry about being the new guy - we all expect new people to show up for the open runs and we wouldn't hold an open run if we weren't willing to spend some time sharing what we learned from other people that did the same for us.
Absolutely go out for the Jeep 101 - even if you've been on a number of open runs, you'll be amazed at how much you learn. The whole event is designed to teach folks that are new to the sport.