How do i make a teleport GUI?

Yes. Having an MouseButton1Downevent run with a button in a GUI that then accesses the Players character and moves them.

--Put this inside a LocalScript, and then put it in a button inside of a GUI
position = Vector3.new(0,0,0) -- Change the position to your liking
script.Parent.MouseButton1Down:connect(function() -- When the button is clicked
    player = game.Players.LocalPlayer -- The player
    player.Character:MoveTo(position) -- Moving them
end)