How do I make nametags for moderation of my game?

I’m trying to make a nametags system for moderation where when you press a GUI button you can see player names and their user ID through walls.

I have no idea how to insert a billboard gui or so with text in all characters and that it gets removed if the player leaves the server. And that it is only displayed to the person who activated the nametags can see it.

make it happen on the client with a local script so it doesnt show for other players