How do i Turn off when i press the GUI again?

The best way to do this, in my opinion, is saving the event as a RBXScriptConnection in a variable, then disconnecting it.

Example:

local botao = script.Parent.TextButton
local player = game.Players.LocalPlayer
local nome = player.Name
ligado = false
-- Connection variable, to store the RBXScriptConnection in.
local connection

botao.MouseButton1Down:connect(function()
	if ligado == false then
        	local mouse = player:GetMouse()
		-- When we hook onto the event, set the connection variable to the function we're calling
     		connection = mouse.Button1Down:connect(function()
        		local loca = mouse.Hit.p
        		workspace[nome].HumanoidRootPart.CFrame = CFrame.new(loca)
        		ligado = true
        	end)
        elseif ligado == true then
    		local mouse = player:GetMouse()
    		ligado = false
		-- Disconnect from the connection
		connection:Disconnect()
end
end)

You can read more about RBXScriptConnection here!