Glad you asked that before I did.
We have wintered in Mexico for more than 30 years. We eat everywhere, taco stands to very fine dining restaurants. We do the same thing in Mexico that we do in the US. If there is any doubt in our minds about sanitation, we check the bathroom. If it's not clean, forget it. If at taco stand, we ask to wash our hands. There is almost always a place. Then watch to see if money and food are handled by the same person. Bet they aren't!
Meat? Some very very good stuff now, and very different things, too. Some states even vaccinate their pigs more than we do in the US. Cook it like you like it, or not. We've had some spectacular tartars in restaurants, and what about ceviche??
We got tired of the 5 gallon jugs of potable water. Yes, they are everywhere and cheap. We top up our tank water like tony lee does-where it is available from a faucet or hose. Under our kitchen sink, feeding a little tap by the sink, just like in many houses, we have two filters. One is a real cheap one, the second, a .5 micron filter. That's it. That's what we and our pets drink and use for ice and cooking. No mess, no hassle, never been sick. The two filters generally last 4 months, but we carry spares just in case. When pressure drops, it's time to change them. We got our information from own little water district.
Fuel, easy, plentiful.
I'm surprised no one has mentioned money. Credit card use is becoming more and more common, even at many Pemex. Be sure that your card does not charge for international use. We use Capital One, but there have been MANY discussions on this topic on this board.
ATM cards are the easiest, safest and have the best exchange rate, for getting cash. Again, check with your bank about fees. We ended our 55 year relationship with Bank of America in November when they started charging 3% for use out of the US. We are now with CapOne 360, with no charges. Again, there have been MANY discussions on this topic on this board.
Go to Mexico. Have a great time. Don't over think it, just don't do anything you wouldn't do at home. Enjoy the adventure.