How do you make the arm follow the mouse when holding a tool?

How do you make the arm follow your mouse when holding the tool? For example... UristMcSpark's pistol. Do I either have to use CFrame or something wayy more advanced. I do not know that much math in doing this, simply because I am way younger than 13, but the only one I have tried is Mouse.Move. I do not know that much functions or keywords in that matter, but that is the only way I know. This script was put in StarterPack but it did not move otherwise. If you have any other solution to this, respond and thanks in advance.

local player = game.Players.LocalPlayer
local character = player:GetCharacter()
local rarm = character:WaitForChild("Right Arm")
local mouse = player:GetMouse
local rarmCFrame = rarm.CFrame

mouse.Move:Connect(function()
    print("Mouse moved.")
    rarm.CFrame = CFrame.new(mouse.CFrame)
end)

Have tried but nothing shows up in the output.