Forming a business in Texas, there are several ways. As a Texas business owner, both from prior to our RV life and still, currently, as full-time RVers, I'll tell you it's not very difficult.
You can use something like LegalZoom if you want to pay a little extra and have them manage it all. Otherwise, it's just a matter of filling out the forms. For small biz, I suggest LLC, but your scenario may be different. You can find the forms here:
https://www.sos.state.tx.us/corp/forms_boc.shtml
Just a note, too, you'll need to file with the Texas Comptroller each year saying "I didn't make over a million dollars" basically (unless you did). There are certainly more tax implications, requirements, etc. but these are the basics to get you going. Disclaimer: I'm not a lawyer, accountant, tax person, none of those things. Please utilize your best resources to protect yourself.
Good luck!