Comida is the Spanish word for "food".
comida
comida
comida
comida
La comida
(La) comida.
"Quiero comida."
Comida buena.
condimento(s)
Since guacamole is a Spanish food, the word is already in Spanish.
Are you asking what the main food is of Spanish-speaking people? Or are you asking how to say the words "main food" in Spanish? Please clarify your question. But the main food of Spanish-speaking people is different from one Spanish-speaking country to another.