Conner didn't really have any strong feelings about clowns.
But after one smothered him into unconsciousness with a handful of colorful hankies and he woke up tied to a chair surrounded by slashers, he's formed an opinion.
The clown in question, Bloody Bettina, wants nothing more than to hunt him down in a maze of broken-down RVs with her slasher friends. They want to spill his blood, sever his limbs, eat his heart, you get the picture.
But when he manages to survive their death maze, Bloody Bettina is so impressed that she decides to take him on as her apprentice. Conner doesn't understand all that entails but having no other good option, he accepts.
Now he has to make it through Bloody Bettina's lessons, deal with an enemy he somehow created on day one of training, protect a sidekick he didn't ask for, and survive the ire of the clown's slasher friends, who aren't thrilled with him being added to their group.