It is possible to get to Emiliano Zapata through the somewhat larger village of San Quentin.
Walking and maybe horseback
Emiliano Zapata has a limited supply of groceries. While the small shops don't have a great selection, they do have enough that you do not need to pack in a lot of food with you unless you particularly want to cook a special meal.
There are a few "restaurants" in the village. Each is a person's house with a large table where you are invited to wait while they cook something up for you in their kitchen (often times over an open fire). Prices vary, so ask before ordering.
Alcohol is allowed in the village so beer and tequila is widely available.
The town has setup 6 small cottages and a communal palapa where visitors can sleep. The cottages have a tendency to attract cockroaches, tarantulas and scorpions so unless you really want to have a mattress, sleeping outside under the palapa is preferable.
There is no way to contact the village in advance to make reservations (either by email or by phone). Simple show up and ask for "El Presidente de Turismo."