Texas State Parks hosts a "Free Fishing in State Parks" year-round program to encourage more families to enjoy one of America's greatest pastimes. There is no license required at the locations listed on their website:
https://tpwd.texas.gov/fishboat/fish/programs/familyfish/stateparks/
Here is a guide for the beginning angler that includes instructions on cleaning:
https://tpwd.texas.gov/publications/pwdpubs/media/pwd_bk_k0700_0639d.pdf
A recipe for your Catch of the Day:
https://www.tasteofhome.com/recipes/mom-s-fried-fish