How to make a part point to a player?

I am trying to make a part that points to the player where ever they move, I have tried using, https://developer.roblox.com/en-us/articles/Understanding-CFrame, To get a better understanding of cframe. I have made a script but nothing comes up in the output, neither does the cube move, does anyone know how to answer this?

wait (2)
local cube = game.Workspace.Cube
local player = game.Players.LocalPlayer.Name


local targetPosition = player.HumanoidRootPart.Position


while true do
cube.CFrame = CFrame.new(cube.Position, targetPosition)

	end

You got the right idea with the CFrame, but some of your other logic is off.

wait(2);
local cube = game:GetService("Workspace").Cube;
local plr = game:GetService("Players").LocalPlayer;

local targetPos;
while wait() do
	targetPos = Vector3.new(0,0,0);
	if plr.Character then
		targetPos = plr.Character.HumanoidRootPart.Position;
	end

	cube.CFrame = CFrame.new(cube.Position, targetPos);
end