Hello, you can simply use CameraOffset in the Humanoid.
game.Players.LocalPlayer.Character.Humanoid.CameraOffset = Vector3.new(0,0,0) -- Default to set it back
game.Players.LocalPlayer.Character.Humanoid.CameraOffset = Vector3.new(3,1,5) -- You can just change these values to mess with the camera!
Also, this would work for calculating the distance between them, like he said.
local Distance = (playerpos - monsterpos).magnitude
This would be in studs if you were wondering. ^
Also, if you were wondering, yes, it works in First Person and Third Person.