you can wear a dress and blazer with flats please dont say "I don't have no slacks" its a double negative good luck with the job interview
First of all, you need to learn how to talk properly and write properly or what you wear to the interview won't even matter. Even at Taco Bell. A dress and a blazer are fine as long as the dress is not too short or tight. Don't even think of going bare-legged to this interview. You need to wear beige or nude sheer pantyhose. Flats won't cut it. You're a big girl now so wear big girl shoes. Wear tall heels. Flats are for little girls. :-)
Yes, a dress with a blazer and flats like Merlin suggested is good advice. Overall, try to look neat and tidy. Also, when you first meet the manager smile and shake their hand. If they ask "how are you? say something like "happy to be here." If you want to stand out and and be "on topic" with the setting (Taco Bell) maybe say something like "taco'rrific" (instead of terrific). Chances are the manager will smile and remember you more than other applicants. I think this is okay for the job/setting; cashiers at Taco Bell near me (Tampa, Florida) say phrases like this when greeting customers. Regardless, remember to smile, and before you leave tell the manager "thank you for the opportunity." Good luck and I hope you get the job'burrito!
Other than what was already suggested, for more interview attire tips, see See as well for interview tips.