How do I add keydown values to this script and local script?

Hey there. I am trying to script magic weapons but I have no knowledge of how to add keydown values to my script. How would I convert left clicking to a keydown value?

--this is my script

local Tool = script.Parent
play = Tool.Parent.Parent 
char = play.Character
hum = char.Humanoid 
root = char.HumanoidRootPart

local en = true


Tool.RemoteEvent.OnServerEvent:connect(function(play,mousehit)
 local a = hum:LoadAnimation(Tool.RedMagic2)
 a:Play()
 root.CFrame = CFrame.new(root.Position,root.Position + Vector3.new(mousehit.lookVector.x,0,mousehit.lookVector.z))
 wait(0.7)
 local f = Tool.Handle:clone()
 f.CFrame = Tool.Handle.CFrame
 local bv = Instance.new("BodyVelocity")
 bv.MaxForce = Vector3.new(1e8,1e8,1e8)
 bv.Velocity = mousehit.lookVector * 50
 bv.Parent = f
 f.CanCollide = false
 f.Parent = game.Workspace
 game.Debris:AddItem(f,4)
 local ten = true
 f.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(10)
 elseif hit.Anchored  == true and hit.CanCollide == true then
  for i=1,10 do
   local part = f:clone()
   part.Size = Vector3.new(0.5,0.5,0.5)
   part.CFrame = f.CFrame
   part.BodyVelcoity.MaxForce = Vector3.new(1e8,0,1e8)
   part.ParticleEmitter.LockedToPart = false
   part.BodyVelocity.Velocity = Vector3.new(math.random(-30,30),math.random(-30,30),math.random(-30,30))
   part.Parent = game.Workspace
   game.Debris:AddItem(part,1)
  end
 end
 wait()
 ten = true
 end)
end)

-- this is my local script

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

local en = true
Tool.Activated:connect(function()
 if not en then return end
 en = false
 Tool.RemoteEvent:FireServer(mouse.Hit)
 wait(3)
 en = true
end)