MAIN CHARACTERS - Screenwriting

Say you develop a world, characters, everything fits together.  But you can't come up with a conflict... because everything thing fits together.

That world is your "second act" world.  Your "underworld"

Brainstorm some characters who would NOT fit in with these characters.

A character who preaches opposite ideals.

A character who looks different

A character who's not welcome.

That's your main character and that's your first act.