How can I make my intro not show up after you reset or die?

What you should do is add a boolean value in the Player (when they join), thats something like "ViewedIntro", and when the intro has been viewed, have it go into the Player and check if said value is true or not before it plays the intro, if true, it removes the GUI, else, plays the GUI and sets the value to true, something like:

local legui = script.Intro:Clone()
game.Players.PlayerAdded:connect(function(player)
	player.CharacterAdded:wait()
	if player:FindFirstChild("ViewedIntro") then
		if player.ViewedIntro.Value == true then return end
	else
		local newgui = legui:Clone()
		newgui.Parent = player.PlayerGui
		newgui.LocalScriptsName.Disabled = false	--[ Change "LocalScriptsName" to the name of the script in the GUI. ]
	end
end)

And for the GUI's code (Have the script's Disabled property set to true in the GUI):

local Screen = script.Parent
local Player = Screen.Parent.Parent
local Config = Screen.Config
local Filter = Screen.Filter
local Content = Screen.Content
 if not Player:FindFirstChild("ViewedIntro") then
	local HasViewed = Instance.new("BoolValue", Player)
	HasViewed.Value = true;
elseif Player:FindFirstChild("ViewedIntro") and Player.ViewedIntro.Value == true then
	Screen:remove()
end

function FilterFade(start,finish,step)
	for i = start,finish,0.03/step do
		Filter.BackgroundTransparency = i
		wait()
	end
	Filter.BackgroundTransparency = finish
end
 
Filter.Visible = true
for _,image in pairs(Content:GetChildren()) do image.Visible = false end
wait(Config.Padding_Time.Value)

for _,image in pairs(Content:GetChildren()) do
	image.Visible = true
	FilterFade(0,1,Config.Fade_Time.Value)
	wait(Config.Display_Time.Value)
	FilterFade(1,0,-Config.Fade_Time.Value)
	image.Visible = false
	wait(Config.Display_Time.Value)
end

wait(Config.Padding_Time.Value)
Screen.Background.Visible = false
FilterFade(0,1,Config.Fade_Time.Value)

Screen:remove()

Hope that helped (and worked), :) Regards, Xetrax