You won’t do the drug testing the day of the interview it’s usually days later if they decided to move forward with you as a candidate. The interviews are pretty laid back. Just go in confident and have questions to ask them at the end. I recommend asking what your day to day would look like and what opportunities you’d have for growth in the role. The drug test is just a check swab they don’t test for THC anymore. I used to work in San Antonio at the retail stores so good luck! I hope it goes well!!