Looking at their menu....not a lot of choices. Seems like they don't really have any non tortilla based meals.
I would recommend some black beans, soup, and thier spinach salad doesn't look bad if you can tolerate that now.
You could also always get a taco plate and just try to eat the insides.
Another suggestion is to see if you can order something a la carte. Then just order 1 chicken taco and maybe a few black beans for an example (if you can tolerate solids now).
If not....go with some refried beans and soup!
Definitely avoid any tortillas (corn or flour doesn't matter), tough veggies (peppers etc), chips, etc.
Congrats on your weight loss....you are doing wonderful.