The dev console says line five is'nt working, why?

local Tool = script.Parent
play = Tool.Parent.Parent
mouse = play:GetMouse()
char = play.Character
hum = char.Humanoid
root = char.HumanoidRootPart


local en = true

Tool.RemoteEvent.OnServerEvent:connect(function(play,mousehit)
	local a = hum:LoadAnimation(Tool.Throw)
	a:Play()
	root.Cframe = CFrame.new(root.Position,root.Position + Vector3.new(mousehit.lookVector.x,0,mousehit.lookVector,z))
	wait (.7)
	local fireball = Tool.Handle.clone()
	fireball.CFrame = Tool.Handle.CFrame
	local bv = Instance.new("BodyVelocity")
	bv.MaxForce = Vector3.new(1e8,1e8,1e8)
	bv.Velocity = mousehit.lookVector * 50
	bv.Parent = fireball
	fireball.CanCollide = false
	fireball.Parent = game.Workspace
	game.Debris:AddItem(fireball,4)
	local ten = true
	fireball.Touched:connect(function(hit)
		if not ten then return end
		ten = false
		local ehum = hit.Parent:findFirstChild("Humanoid")or hit.Parent.Parent:findFirstChild("Humanoid")
		if ehum and ehum ~= hum then
			ehum:TakeDamage(20)
		elseif hit.Anchored ==true and hit.CanCollide==true then
			for i=1, 30 do
				local part = fireball:clone()
				part.Size = Vector3.new(1,1,1)
				part.CFrame = fireball.CFrame
				--part.BodyVelocity.MaxForce = Vector3.new(1e8,1e8,1e8)
				part.ParticleEmitter.LockedToPart = false
				part.BodyVelocity.Velocity = Vector3.new(math.random(-30,30),math.random(-30,30),math.random(-30,30))
				game.Debris:AddItem(part,1)
			end	
		end
		
		wait()
		ten = true
		
	end)
	end)

Also says that line five "attempts to index global index"

You can't assume that the player has a loaded character. Make good use of functions like WaitForChild.

local Tool = script.Parent
play = Tool.Parent.Parent
mouse = play:GetMouse()
char = play.Character or play.CharacterAdded:wait()
hum = char:WaitForChild("Humanoid")
root = char:WaitForChild("HumanoidRootPart")

Try replacing the play, char and humanoid with this

local Player = game:GetService'Players'.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait()
local Human = Character:WaitForChild("Humanoid")

you have to that because the char dont load as soon as the script does