Welcome to Austin. The three places that we go ride are:
1) CTOR (
http://ridector.com/) - 30 minutes north of Austin. $20 a day to ride or $300 a year. 1,000 acre ranch. They have a lot of trails and it is only dirt bike and 4 wheelers. Great place to ride with all skill levels. Check out the videos on the site to see what it is like. We are members out there and love it since we can camp overnight and get our camping and dirt bike riding fix at one time.
2) Hidden Falls Adventure Park (
http://www.hiddenfallsadventurepark.com/) - 45 minutes west of Austin. $20 a day (I think) to ride. 3,000 acre ranch. Tons a trails (I think it has 80 miles of trails). A lot of single track and creek beds to ride in. Very rocks and can be rather technical. This is where they host one of the enduro races. Love this place, but it can get super dusty and has a lot of other traffic since it is open to 4 wheel drive vehicles as well. If you like rocks this is your place.
3) Murphy's MX Park (
http://www.murphysmx.com/) - an hour and a half southeast of Austin. $25 a day to ride. Great motocross track (day and night track plus a kids track and a few trails). Amazing dirt and forgiving for a motocross track.
There is also Del Valley Motocross (
http://www.advmxpark.com/) - 20 minutes southeast of Austin near the Circuit of the Americas F1 track. $25 a day to ride. Serious motocross track (big jumps and fast riders). This is where a lot of motocross races are held around the area. I am not that good or that fast so I tend to stay away from Del Valley, but if you know how to ride well you will have a blast.
What sort of riding are you looking to do? Is it just you or do you also have kids that ride? Just curious to help guide you in the direction to go. As for the best bar to hang out at, I usually just do it out at the track at the end of the day after the riding is done. Let me know if there is anything else I can do to help.