Not sure about clubs in Houston anymore; a couple of years ago we had an active club (Wild Carp Club of Houston) but the umbrella organization folded and the main local organizer, Nick Davis, relocated to Ohio.
I'm in Dallas now, so I can clue you in to some of the better swims but do not know about the fishing activity anymore.
There are plenty of grass carp in all of the bayous, including Buffalo Bayou downtown. There have also been a few commons caught there, into the low teens.
The lower stretches of Greens, Braes, and Sims bayous hold good populations, but being close to he ship channel the locations can be somewhat dodgy, especially after dark. One of my favorites is Braes Bayou just north east of I-45 south, off Wayside and Sylvan. There is a nice little park there. Up to 20lbs but avg low teens.
For overnight you can try the Lake Houston Marina, but be forewarned it can be busy. Up to 25lb have been caught, both commons and grassers.
Lake Woodlands has a low stock of commons to near thirty, but you have to work for them.
Small commons and sm buffalo to near 30lbs have been caught in Sugarland off Hwy 6 and Fluor Daniel.
What part of Houston are you in?