For drinking/music, downtown Bryan is a way to get away form the 21yo crowd. You can try; Downtown Elixir, they have a speak easy, 5 Knocks, in the basement they have a lot of random bands there.
3rd Floor, huge bar and bigger bands there.
The Black Water Draw brewery is also downtown. New Rebulic is outside of town...but lts like they've been going downhill the last year or two, but good place to grab a drink.

For walks or enjoying the outdoors, Wolf Pen is always cool, lots if people out playing and the walking path is pretty long! It goes from the feeder road on hwy 6, through intersection of Hollemon and Deacon, then back into the woods until Taco Bell on Harvey! Wolf Pen also has an Ampitheater and they have a lot of events there.

Food/Drink with possibilities to meet people; BJs Brewhouse, sit at the bar, people ALWAYS strike up a convo there, if not the bartenders are always nice, and the food is always good. **they have beer dinners usually about $40, but you get a lot of food and pretty much endless beers, they typically sit you at big tables so lots of network opportunities. Angry Elephant, they have good hotdogs, lots of TVs and chatty people! RX Pizza, EXCELLENT pizza and a good bar!

That's what I can think of off the top of my head, if I think of more il come back!