Learn Spanish (Spain): Me gusta la fiesta porque la gente es muy interesante. - I like the party because the people are very interesting.

We use muy (very) because it comes right before an adjective (interesante). You only use mucho or its matching forms (mucha, muchos, muchas) when you are describing quantities of nouns (meaning "a lot of" or "many"), or right after a verb to mean doing something "a lot".

Why does the sentence say la gente es (the people is) instead of using a plural verb?

In Spanish, the word la gente (people) is a singular feminine noun. It works a bit like the English word "crowd" or "group". Even though it refers to many individuals, the word itself is singular, so you must use the singular verb es (is).

Does the adjective interesante need to change its ending to match the feminine noun la gente?

No, because adjectives that end in -e in Spanish (like interesante, grande, or inteligente) are gender-neutral. They use the exact same form for both masculine and feminine nouns. You only need to make sure it is singular (no -s at the end) to match the singular noun la gente.

Just to refresh, why is it Me gusta la fiesta instead of Yo gusto la fiesta?