A common restaurant destination in Guatemala is the comedor, a rougher version of the common North American diner. Here you will find one or two daily specials as well as a menu of a few standard authentic dishes. These dishes will often times include a fried meat, carne asada or carne frita, vegetables, and/or a broth, also known as caldo. Eggs, beans, and tortillas are common everywhere as well.
For higher end dinging there are restaurants, or restaurantes, which generally offer a more varied selection either with a menu or a prearranged daily plate, or menu de día. Also, any major city will likely have a few more diverse options, such as international cuisine.
Finally, another option is always the common street side vendors selling anything from tacos to tamales to pupusas, a stuffed tortilla with meat and/or vegetables on top.