Spirit Camp (2009)

When a street smart "goth girl" (Roxy Vandiver) is forced to attend cheerleader camp as part of her rehabilitation from a juvenile correction facility, she clashes with the "popular girls," and finds herself embroiled in a bitter rivalry with the bitchy ringleader Rachel (Julin). But when members of the spirit squad start turning up dead, the girls must put aside their differences and struggle to survive the murderous rage of a crazed psycho-killer lurking among them!

Unfortunately the movie Spirit Camp is not yet available on HBO Max.