How do I store the gui somewhere else for later use?

Here is your script hopefully fixed, use a serverscript under dummy

If that does not work try this but put your ClickDetector in the Dummy's torso.

The script just get the player who clicked in the event and get there GUI and make it visible.

So on your line local Click = game.Workspace.Dummy.ClickDetector Player = game.Players.LocalPlayer

You shouldn't get the LocalPlayer over a ServerScript. The LocalPlayer is only used for LocalScripts. The MouseClick event already gives you the player so you would not need it.

I think a ClickDetector only works under a part, so if that does not work use the other codeblock.

You can ask me clarification anytime :)

ScreenGuis all have a property called Enabled. You can use this to say wether a ScreenGui will be visible or not.