how can i make a view model to be visible when i use the tool?

how i can do it? me is making viewmodel aslo i dont know lua :C

here is script

local player = game.Players.LocalPlayer

local char = script.Parent

local cam = workspace.Camera

local run = game:GetService("RunService")

local arms = game.ReplicatedFirst.Arms:Clone()

run.RenderStepped:Connect(function()

    arms:SetPrimaryPartCFrame(cam.CFrame * CFrame.new(0,-1.5,0))

end)

arms.Parent = cam