I wanted to enjoy the long weekend too, but thanks to a certain group of six's make-up classes and prep, I had no long weekend at all!

Literal

Teacher [also-も] long-weekend [object-を] enjoy-wanted [but-が], somewhere [attributive-の] six-person-set [attributive-の] remedial-classes [and-such-やら] preparations [and-such-やら] [because-of-で] long-weekend not-exist-[past-なかった][masculine-ぞ]!

A teacher addressing students, using 先生 self-referentially — a common Japanese speech convention where teachers, parents, doctors, and other role-figures refer to themselves by their role rather than 私 or 俺. The listing particle ~やら~やら lists items with a nuance of grumbly exasperation ('all the X and Y and such'). どっか is casual for どこか; 組 is a group/set counter ('a set of six'). エンジョイする is a wasei loanword verb. ~ぞ is the masculine assertive sentence-ender.