Quentin's father is trying to kill him
Source: Quentin's father knew the high school was literally haunted all along, as evidenced by the fact that he taught his son a spell as a lullaby just in case. Yet he still sent his son to this high school. This private high school. That costs money. A lot of money.
Why does Quentin's father want him dead
Also tbh if my dad were a serial killer I would not stay in the town my dad had serial killed in so.