I don’t see any recommendations for The Lost Boys yet. It’s super '80s in the “both Coreys” way. It’s dated, but still a lot of fun.
Prince of Darkness is a guilty pleasure for me. I love religious horror, so it’s my favorite John Carpenter movie. There are some fairly violent bits, but it’s not overly gory like a slasher flick. If you’re okay with The Thing, this one should be fine.
The Endless is also religious horror, but it’s more psychological. There’s not much violence, but it’s very tense.
Little Monsters (the 2019 one) is a heartwarming comedy about a teacher who has to protect her class from a zombie apocalypse during a field trip. It’s got a moderate amount of zombie-movie gore, but it’s treated in a humorous way. If you’re okay with Shaun of the Dead, it should be fine.
They do. There are a few elite non-religious private schools in Louisville.
But they are far outnumbered by parochial schools.