How do I make a money GUI with the .Changed function script I have?

I have this script:

Cash.Changed:connect(function() Label.Text = '$'..tostring(Cash.Value) end)

Should I put this in a local script or just a script?

Is there anything I need to add to the script to make the money GUI work?

Local scripts are usually what you want to use in a Gui, especially with Filtering Enabled on.

Assuming this is your hierarchy, then here is the following code;

I have set up two variables to define the location of both the TextLabel, and the Points.

local Label = game.Players.LocalPlayer.PlayerGui.ScreenGui:FindFirstChild('TextLabel')
local Cash = game.Players.LocalPlayer.leaderstats:FindFirstChild('Points')

I am connecting to the event, .Changed, the function will run once the IntValue has changed.

Cash.Changed:Connect(function() 

Now because the IntValue was .Changed, the Label will update itself to whatever the Cash.Value is equal to.

Label.Text = '$'..tostring(Cash.Value)
end)

Full code;

local Label = game.Players.LocalPlayer.PlayerGui.ScreenGui:FindFirstChild('TextLabel')
local Cash = game.Players.LocalPlayer.leaderstats:FindFirstChild('Points')

Cash.Changed:Connect(function() 
Label.Text = '$'..tostring(Cash.Value)
end)

This code should be in a localscript.

Also, It has been pointed out to me that instead of :connect, you should be using :Connect as it has since been deprecated. The same thing with the signal events, disconnect and wait.

Hope this helps! Don't forget to accept my answer if this works for you, or leave a comment if you need further assistance!