State of Texas has a cottage food industry law, but it is illegal to sell any type of meat products from a home based business. One of the biggies is if you're cooking it at home and not in a restaurant/food truck situation, then you can't sell meat, period and nothing else that requires temp control (must be kept hot or cold). Also other weird stuff.
https://texascottagefoodlaw.com/Definitely get the details from the food truck people. I have a few friends that did this years ago, and I am pretty sure you have to get a food handler/catering license, and have regular inspections in order to not be on the wrong side of the law. And you'll also want to make sure and get insurance for a small business so that folks can't wipe you out if you end up having someone sue you for food poisoning or such (Texas is a pretty nice state, but there are also many assholes unfortunately).