There is a phone app called "Launch Sites" that uses your GPS location and shows you put-in places around your location. Some locations have user added comments about the facilities and the location in general. It might give you some ideas on what is around you to the point where you can do further research. Also, if you check out the Texas Parks and Wildlife page you should be able to find well marked water trails in Texas. If you'd like to do a river trail but you only have one vehicle you can always find a canoe livery that will transport your gear for you. When I've done this in Ohio they usually charge you a fee of 50% of the rental cost. Beats driving two of your own vehicles most times.