Charlie,
Welcome!
I'd definitely welcome a beginner like you, but then again I'm not very far ahead of you, if any
First, the riding around Austin will probably be a bit disappointing after coming from Mojave
That sounds like an awesome trip, all except for the two broken wrists
As you might see from the map there isn't a heck of a lot of real off road close to town. Texas is mostly private property so unlike states with large tracts of Nat'l Forrest or BLM it can be a bit tough to find good off road riding. There are a fair handful of off road parks around, including Hidden Falls up by Marble Falls. I haven't been to any of them but they look and sound fun... costs money to play there though. Close to town is mostly a few dirt roads which seem to get better the further west you go. (Speaking of west, even the tarmac out past 281 towards and beyond Fredericksburg can be really fun...) There is a group around that does urban dual sport riding on little bits that they find. I think those guys hang out on ridedualsport.com these days.
Bike choice is tough in this environment. There can be quite a bit of slab before you hit dirt. I like the DRZ and it's fat cousin the DR (I have a DR). Old technology, carbs, no 6th gear, but pretty bullet proof and cheap. If I was in a state with more off road and I could only pick one bike, it probably would have been the DRZ. But I'm here, so I picked the DR. If I had the coin I'd consider a Husky TE610/630, but who knows after Richard's latest experience on the Texas Adventure Ride
Of course you will get as many opinions as people that have bikes on this.
The big thing on this forum seems to be hooking up with a handful (sometimes big handful) of guys and girls and doing destinations. Richard has a Mexico ride going out next month that is highly anticipated every year. He also runs one to Big Bend, and other groups go out to New Mexico or Arkansas, etc. Some guys ride to them and some trailer.
What part of Central ATX are you in? Thursdays a TWT group meets at Billy's on Burnet for lunch at 11:30. You could meet some of the usual suspects there
Take it easy, don't be a stranger,
Justin