A simple business or commercial license should be good enough if you plan to repair computers as an occupation.My cousin has a laptop repair store in the Dallas-Fort Worth area where he also runs repair programs.For both of these, a business license was good enough.
A license? Never herd of a license requirement to fix computers. I am not familiar with Texas law, so things might be different down there.You need to be a certified repair place for warranty work. You also have to have know what you are doing while making repairs, so a degree in computer repair is highly advised.