The human versions of the ponies in Equestria Girls attend Canterlot High.
Canterlot High School is the main school setting of the Equestria Girls films and related specials. In the parallel human world, familiar characters such as Applejack, Rainbow Dash, Fluttershy, Pinkie Pie, and Rarity appear as teenagers rather than ponies, while keeping recognizable personalities, relationships, and visual motifs.
The first Equestria Girls film, released in 2013, establishes Canterlot High as the school where these human counterparts live and study. Sunset Shimmer is also a central Canterlot High student, while Princess Twilight visits from Equestria and becomes involved in the school’s conflicts.
Crystal Prep is the most likely source of confusion. It is a rival school featured prominently in My Little Pony: Equestria Girls—Friendship Games, especially through the human counterpart of Twilight Sparkle. Ponyville High and Cloudsdale High are not the standard school setting for the main Equestria Girls cast.