In Mexico, you don’t just go to the supermarket and buy everything you need (well, you can sort of, if you like your fresh fruits and vegetables a week old and tasting like the rubber tires in the next aisle over.)
Most people shop the mercado (fresh market) where vendors sell everything from “fresh from their garden” fruits and vegetables, to meats, eggs, cheese, dairy products, herbs, dried fruits and nuts, masa (for making tortillas), housewares, hardware, clothing, and even handmade shoes. If you need it, someone will sell it.
In my house, the day to go to the mercado is Monday, that is because in addition to the main mercado downtown, there is a small mercado just around the corner. It is much easier to buy and transport heavy fruits and vegetables home from there than halfway across town. We load up on everything we think we will need for the week. On Mondays we eat like kings but sometimes by Sunday it is slim pickin’s.
Here is a tour of a Mexican mercado.