Why is this GUI /sound script not working when I touch this brick?

LocalPlayer is LOCAL SCRIPT ONLY! This means you can't use a Script if you want to link it to LocalPlayer.

However, there is another way to do this. We just need to find the player who touched the brick. If there is no such player, the function does nothing.

Here, let me show you the script.

script.parent.Touched:connect(function(hitObject) -- The touched event returns the object that it touches.
    local player = game.Players:FindFirstChild(hitObject.Parent.Name) -- The player is a model in Workspace. However, the hitObject only returns what PART of the player it touches, i.e. Left Leg, Torso, Right Arm.
    if player then
    	local s = Instance.new("ScreenGui", player:WaitForChild("PlayerGui"))
    	local i = Instance.new("ImageLabel", s) -- You have already made a reference to the "ScreenGui"
    	i.Image = "rbxgameasset://Images/fat fedora guy"
    	i.Size = UDim2.new(0.559, 0,0.683, 0)
    	i.Position =UDim2.new(0.211, 0,0.089, 0)
    	local m = Instance.new("Sound", game.Workspace)
    	m.Volume = 1
    	m.SoundId = "http://www.roblox.com/asset/?id=256126911" --Recommended!
    	m:Play()
   	 wait(5)
    	s:Destroy()
    	i:Destroy()
    	m:Destroy()
    end
end)

If you have any questions, please leave a comment down below. Thank you and I hope this will help you!