Player looks at a pawn and the pawn starts chasing the player

I want to make a quick jumpscare. An enemy spawns behind you and when you turn around and look at the enemy it starts chasing you. Does anybody know how to make that?

Hi @Kajmak999, welcome to the forums. As a starting point, here are 2 basic options, that you can use. Check the docs for Line Trace By Channel and for AI Perception.
The latter is somewhat more involved and may be too advanced for what you want to achieve, but it is worth checking out anyway.
Edit: a Line Trace By Object could be a better alternative in your case.