Script not executing after function was added?

local Player = game.Players.LocalPlayer
local ssye =  Player.PlayerGui

Player.CharacterAdded:connect(function(character) --Instead of this, I'd recommend having a BoolValue tell us once ready. Your choice
    character.Humanoid.WalkSpeed = 0
    character.Humanoid.JumpPower = 0
    wait(6)
    ssye.Intro.Load:Destroy()
    ssye.Intro.Reminder:Destroy()
    wait(3)
    local back = ssye.Intro.Background
    for  i=1, 10  do
        back.BackgroundTransparency = back.BackgroundTransparency +  .1
        wait(.1)
    end
    game.ServerStorage.DBZPicture:Clone().Parent =Player.PlayerGui.Intro
    game.ServerStorage.DS:Play()
    wait(5)
    ssye.Intro.DBZPicture:Destroy()
    wait()
    script.Disabled = true -- This will disable the script. In short, it will only run once. Keep this at the end of the code

end)

Not here to spoonfeed you, but all you did was placing ssye in the PlayerGui?? I think you need a ScreenGui and then you can do whatever you want.

Player = game.Players.LocalPlayer
PlayerGui = Player.PlayerGui.ScreenGui...

This is in a LocalScript, this will ONLY work in a Client Script in workspace, so do not use localplayer,

instead do this

function OnPlayerEntered(player)
ssye = player.PlayerGui