How do you detect when a player clicks a button twice to trigger two different functions?

i think you should do like this:

local Button = script.Parent
local Click = script.Parent.Click
local State = script.Parent.State

function onClick()
    Button.CFrame = CFrame.new(Button.Position - Vector3.new(0, 0.2, 0))
    wait(0.01)
    Button.CFrame = CFrame.new(Button.Position + Vector3.new(0, 0.2, 0))
    Click:Play()
    if State.Value == 0 then
        wait(1)
        script.Parent.Parent.One.Light.PointLight.Enabled = true
        script.Parent.Parent.Two.Light.PointLight.Enabled = true
        wait(1)
        script.Parent.Parent.Three.Light.PointLight.Enabled = true
        script.Parent.Parent.Four.Light.PointLight.Enabled = true
        wait(1)
        script.Parent.Parent.Five.Light.PointLight.Enabled = true
        script.Parent.Parent.Six.Light.PointLight.Enabled = true
        wait(1)
        script.Parent.Parent.Seven.Light.PointLight.Enabled = true
        script.Parent.Parent.Eight.Light.PointLight.Enabled = true
        State.Value = 1
    else if State.Value == 1 then
        script.Parent.Parent.One.Light.PointLight.Enabled = false
        script.Parent.Parent.Two.Light.PointLight.Enabled = false
        wait(1)
        script.Parent.Parent.Three.Light.PointLight.Enabled = false
        script.Parent.Parent.Four.Light.PointLight.Enabled = false
        wait(1)
        script.Parent.Parent.Five.Light.PointLight.Enabled = false
        script.Parent.Parent.Six.Light.PointLight.Enabled = false
        wait(1)
        script.Parent.Parent.Seven.Light.PointLight.Enabled = false
        script.Parent.Parent.Eight.Light.PointLight.Enabled = false
        State.Value = 0
    end
    end
end

Button.ClickDetector.MouseClick:connect(onClick)

hope it helps.