Error: Attempt to index a nil value?

title is my error, what is wrong? it says its something in line 3...

game:GetService("Players").PlayerAdded:Connect(function(player)
	local Como = player.PlayerGui:FindFirstChild("Password")
	Como.Enabled = true
	game.Lighting.Blur.Enabled = true
	local Hobo = player.Character:FindFirstChild("Humanoid")
	Hobo.WalkSpeed = 0
end)

Instance:FindFirstChild() returns the instance with the provided name if it exists, or otherwise returns nil. In your case, your call is redundant because you do not check if it returned nil.

GUIs cloned client-side won't replicate to the server (i.e. cloned from game.StarterGui), so the server was unable to find your GUI.

Player.Character is not loaded when game.Players.PlayerAdded fires, try the Player.CharacterAdded event like so:

game.Players.PlayerAdded:Connect(function(Player)
	Player.CharacterAdded:Connect(function(Character)
		-- code
	end)
end)