Why is this player spawning and tool loading script not working?

This script is in a regular (non-local) script, and is supposed to equip a weapon when a game begins.

Everything is defined, however, nothing works. I have no idea why, as output has given me nothing.

Can someone please help me?

Here's the script:

local Player = script.Parent.Parent
local GUI = script.Parent:WaitForChild("Loadout_GUI")
local Playing = game.ServerScriptService.MainGame:WaitForChild("Playing")
local P1 = Player.Classes[GUI.Classy.Value]:WaitForChild("Primary")
local S = Player.Classes[GUI.Classy.Value]:WaitForChild("Secondary")

while wait(0.1) do
	if Playing.Value == true then
		local Primary = game.ServerStorage.Weapons[P1.Value]:clone()
		local Secondary = game.ServerStorage.Weapons[S.Value]:clone()
		Primary.Parent = Player.Backpack
		Secondary.Parent = Player.Backpack
		Player.CameraMode = "LockFirstPerson"
		Player.Character.Humanoid:EquipTool(Player:WaitForChild("Backpack"):WaitForChild(Primary.Name))
		script:Destroy()
	end
end

You may have an infinite yield or Playing may not be true in ServerScriptService.

If GUI is a ScreenGui in StarterGui, then you need to add an additional "Parent" to Player.

local Player = script.Parent.Parent.Parent --script.Parent = ScreenGui --script.Parent.Parent = StarterGui --script.Parent.Parent.Parent = Player

Try assertion as well:

--This code is based on the fact everything in your code is valid and everything is defined.
assert(game.Players:FindFirstChild(script.Parent.Parent.Name), 'Could not find a Player (Player).')
assert(script.Parent:FindFirstChild 'Loadout_GUI', 'Could not find Loadout_GUI (ScreenGui).')
assert(game.ServerScriptService:FindFirstChild 'MainGame', 'Could not find MainGame (Object).')
assert(game.ServerScriptService.MainGame:FindFirstChild 'Playing', 'Could not find Playing (BoolValue).')

assert(script.Parent.Loadout_GUI:FindFirstChild 'Classy', 'Could not find Classy (Value).')
assert(Player:FindFirstChild 'Classes', 'Could not find Classes (Object).')
assert(Player.Classes[Gui.Classy.Value]:FindFirstChild 'Primary', 'Could not find Primary (Object).')
assert(Player.Classes[Gui.Classy.Value]:FindFirstChild 'Secondary', 'Could not find Secondary(Object).')