Staying at the Ruidosa Ghost Town Inn in Big Bend has some extra perks.
A trip to Mexico is easy and safe. You'll drive about 18 miles to Presidio (maybe 30 minutes) and drive across the border into Ojinaga, Mexico. You can also park on the US side, and walk across, but you'll want to hail a taxi, since the shops are a couple of miles away.
A great grocery store called Al Super has a deli, meat market, and of course a bakery. They also sell beer, wine, and liquor.
Please do some homework if you plan to return with alcohol or any foods. There are taxes and limits at the border for alcohol products, and some foods cannot be be brought back, including pork, chicken, and various fruits and vegetables. Many many other items can be freely purchased and returned to the US. You can pick up a list of prohibited food items from the US side of the bridge at the Customs office. The grocery store in Mexico also has a sign hanging from the ceiling with some guidelines as well.
For restaurants, our regulars are: Lobbys, Don Pancho's, Mexico Ayer, Los Comales, and Tacodrilo, plus quite a few street vendors.
If you'd like a guide to help you, Angell Expeditions frequently takes visitors to Mexico.
You need to have a passport, and make sure you and your vehicle are free of firearms, ammo (even spent ammo), or controlled substances.