How can I debounce this? Not really good with them?

-- Assuming state is the value you want to debounce 
local state = false

script.Parent.ClickDetector.mouseClick:connect(function(touched)    

    state = not state
    if state then
    state = true
        script.Parent.Sound:Play()
        wait(1)
        script.Parent.Off.Windows:Play()
        game.Workspace.KEYBASE.Material = ("Neon")
        wait(3)
    state = false
    else
    state = false
        script.Parent.Sound:Play()
        wait(1)
        script.Parent.Off.WindowsOf:Play()
        wait(1)
        game.Workspace.KEYBASE.Material = ("SmoothPlastic")
        wait(4)
    state = true
    end
end)

I'm not too sure what you're trying to do entirely but here's a start. Edit it and see what you can come up with. If not reply with your error.

local state = false

script.Parent.ClickDetector.mouseClick:connect(function(touched)    

    if state == false then
    state= true
        script.Parent.Sound:Play()
        wait(1)
        script.Parent.Off.Windows:Play()
        game.Workspace.KEYBASE.Material = ("Neon")
        wait(3)
    else
        script.Parent.Sound:Play()
        wait(1)
        script.Parent.Off.WindowsOf:Play()
        wait(1)
        game.Workspace.KEYBASE.Material = ("SmoothPlastic")
        wait(4)
    state = false
    end
end)

This should work. Let me know if it doesn't.