how to make this script give damage/hurt npc?i need help it will not do any damage i need help plz?

local enabled = true
Player = script.Parent.Parent
--Player:WaitForDataReady()
mouse = Player:GetMouse()
run = game:GetService("RunService")
function onKeyDown(key)
if not enabled then return end
enabled = false
	Key = key:lower()
	if key == "q" then
		RightShoulder = Player.Character.Torso["Right Shoulder"]
		LeftShoulder = Player.Character.Torso["Left Shoulder"]
		Run = game:GetService("RunService")
			for i = 1, 12 do
				LeftShoulder.C0 = LeftShoulder.C0 *CFrame.Angles(0, 0, -0.10)
				LeftShoulder.C0 = LeftShoulder.C0 *CFrame.Angles(0, -0.1, 0)
				Run.Stepped:wait(0.00)
			end



		wait(0.0)
		for i = 1, 12 do
			LeftShoulder.C0 = LeftShoulder.C0 *CFrame.Angles(0, 0.1, 0)
			LeftShoulder.C0 = LeftShoulder.C0 *CFrame.Angles(0, 0, 0.1)
			Run.Stepped:wait(0.00)
		end
	end
wait(.0)
enabled = true
end

mouse.KeyDown:connect(onKeyDown)