Why does my getchildren line of code keep saying: Attempt to call a nil value?

I'm attempting to make a horror game on Roblox, when you interact with this light switch its supposed to turn them on, but whenever I try it doesn't work, and the output says,"Workspace.Lights.Part.Script:3: attempt to call a nil value" what does this mean?

my code:

script.Parent.ProximityPrompt.Triggered:Connect(function()
	local light = script.Parent.Parent:GetChildren("Light")
	local pointlight = light:GetChildren("PointLight")
	pointlight.Enabled = true
	local click = light:GetChildren("Click")
	click:Play()
	script.Parent.ProximityPrompt.Enabled = false
end)

please help.

For getting a object use :WaitForChild().

Here is the fixed code

script.Parent.ProximityPrompt.Triggered:Connect(function()
    local light = script.Parent.Parent:WaitForChild("Light")
    local pointlight = light:WaitForChild("PointLight")
    pointlight.Enabled = true
    local click = light:WaitForChild("Click")
    click:Play()
    script.Parent.ProximityPrompt.Enabled = false
end)