Adam12SD - this would be a great first run with the group. Just bring a great attitude and your sense of adventure, along with enough gear and supplies to be self sufficient. Just the basics would get you by:
*Some shelter for camping (a tent, or some people just sleep in their rig, plus a sleeping bag, etc)
*Food for yourself and anyone in your group, both on the trail and back at camp. Days on the trail usually result in lunch on the trail, so plan accordingly. Having some extra food is also a good idea, in the event of an emergency.
*Water. Again, have enough for an emergency. The absolute least you should have in the desert is 1 gallon per day per person in your group. More is always good.
*Fuel for your rig. Most folks show up with as full of a tank as possible (aka - filling up at the closest gas station), and bring at least a few extra gallons.
*Firewood for the group fire. Specific amount will be defined as we get closer to the event, but usually one or two bundles per attending rig ends up giving us plenty for a few good nights' fires.
*Anything else that is an "essential" for you or anyone in your group. Think: heaters, portable bathrooms (and toilet paper), air mattress, etc. For example, we will likely be staying where there is no bathrooms. Some people don't mind hiking a distance from camp with a shovel and squatting over a hole. Others prefer to "go" in a more comfortable setting, especially if you have family members in your group. If you know that certain amenities are important to you or anyone in your group, plan accordingly to have them with you. Remember, we'll be in the open desert with pretty much nothing around but ourselves and whatever we bring.
If you don't have a lot of experience dry camping, you'll learn a lot from this group quickly in just a single outing. The key is to not be a burden on the group while you're learning, and that's easily accomplished by bringing the few things I listed above. It's one thing to forget ketchup and ask if anyone in the group has some for your hot dog, but it's another thing to run out of gas on the trail because you were the only one who didn't bring extra fuel. Feel free to ask tons of questions, as everyone here has their own style and their own essentials for trips like this. For example, I prefer to bring a big kitchen setup and cook great food for myself and my family. Celt usually likes to throw some scraps into a piece of foil and set it in the campfire for a few minutes and call it dinner
(or he's been known to pull an MRE out from under his seat during the middle of a day on the trail).
As far as the actual trails and offroading, don't worry, we won't get you into any situations you aren't comfortable with. If you're still learning the capabilities of your rig and yourself, you can stick with the group on the green trails, which are basically dirt fire roads. The last thing you should consider is some kind of communications capability. Most of our group runs Ham radios, but it requires a license before you can operate on one. Getting the license isn't difficult, there are free or cheap study guides that will help you pass the test for the most basic license, but it does take a little bit of a time investment to study and be ready (some people just buckle down and get it done in a day or two, others will study for a few minutes a day for a few weeks before they're ready). There are very inexpensive handheld Ham radio options from China (see: Baofeng). Even if you don't obtain a license before this trip, you can purchase one of the radios for $30 or less and be able to at least monitor the communications taking place within the group you're in. CB is a secondary option, but less and less folks in our group are running CBs these days, so you're far better off with the HAM if you can swing it.
Look forward to seeing you out there!