Well, each region has some of it’s own foods. The Yucatan you can find a lot of seafood. The they also make a sauce called Pibel that they use on pork. tacos are very popular all over Mexico, just like you would think, but they are soft, not the deep fried kind we eat. A very popular taco is Taco Al Pastor the meat is kind of similar to a gyro, but pork. But, you can get tacos with chicken, shredded beef, etc. Chiles (hot peppers) are used in a lot of dishes.
Also, the cocoa bean (chocolate) is basically a Mexican discovery I think, check my history. I think it was the Mayans who cultivated and figured out what to do with it, and the Spanish explorers were fascinated by the foods and desserts and helped spread the deliciousness across the Americas and Europe.
Various mole (said mo-lay) click on mole sauce halfway down the page, are popular in various regions.
My husband swears there is no such thing as a fajita in Mexico and nachos for sure were invented in America. Lol.
So much of Mexican food is very laborous. Tacos, sopés, so many things that you make individual, rather than just one big roast in the oven like an American thanksgiving.
Beans, frijoles are also eaten a lot. Refried beans, bean soaps, frijoles charros is one of my favorites.
Popular desserts are Flan, and Tres Leches cake. Also churros are a Mexican treat of fried dough with sugar.
In terms of beliefs, as mentioned before there are mostly Catholics in the country, about 90% of the population I think. Our lady of Guadalupe is the patron saint of Mexico, or something like that. @bob will know. There is a largeish Jewish community also in Mexico City, about 500,000 I think. Talking about Mexico City, I think it is the most populated city in the world, check me on this too, somewhere around 24 million people live in the city.
Mariachi music is very Mexican, and is played at celebrations, parties, and weddings.