Why is my Round System never working?

I looked at so many tutorials but they only work for 'Printing' or 'Hint's'. Also, I tried to change the hint's to text, but it won't work.

I've tried many things to fix this problem but none of them are doing the trick, so I was wondering if someone could help. Thanks!

Errors: Text won't change. Map's won't load. It will not teleport you to the map.

Code:

local playerNotifications = game.StarterGui.ScreenGui.Frame.TextLabel

function waitForPlayers()
	if game.Players.NumPlayers < 1 then
		playerNotifications.Text = "Waiting for players!"
	end
end

function intermissionTimer()
	if game.Players.NumPlayers > 1 then
		for countDown = 10, 1, -1 do
		playerNotifications.Text = "Intermission: " ..countDown
	end
end

function displayGamemode()
	- Couldn't find code for this.
end

function mapSelection()
	local mapList = game.ReplicatedStorage.Maps:GetChildren()
	local randomMap = math.random(1, #mapList)
	playerNotifications.Text = "Choosing the map!"
	wait(4)
	local mapChosen = mapList[randomMap]
	playerNotifications.Text = "The map is: " ..mapChosen.Name
	local mapClone = mapChosen:Clone()
	mapClone.Parent = game.Workspace
end

function teleportAllPlayers()
	local target = CFrame.new(mapClone.Spawns.Position)
	for i, player in ipairs(game.Players:GetChildren()) do
		player.Character.Torso.CFrame = target + Vector3.new(0, i * 5, 0)
		player.Playing.Value = 1
	end
end

function startingTimer()
	for countDown = 3, 1, -1 do
		playerNotifications.Text = "Game begins in: " ..countDown
	end
end

function roundTimer()
	for countDown = 20, 1, -1 do
		playerNotifications.Text = "Time left: " ..countDown
	end
end

function roundEnded()
	- Couldn't find code for this.
end

function teleportAlivePlayers()
	local target = CFrame.new(workspace.TeleportTarget.Position)
	for i, player in ipairs(game.Players:GetChildren()) do
		player.Character.Torso.CFrame = target + Vector3.new(0, i * 5, 0)
		player.Playing.Value = 0
	end
end

function mapDestroy()
	- Couldn't find code for this.
end

function showResults()
	- Couldn't find code for this.
end

game:GetService('Players').PlayerAdded:connect(function(player)
	player.CharacterAdded:connect(function(character)
		character:WaitForChild("Humanoid").Died:connect(function()
			player.Playing.Value = 0
		end)
	end)
 
	local playing = Instance.new("IntValue", player)
	playing.Value = 0
	playing.Name = "Playing"
end)

while(true) do
      waitForPlayers()
      wait(0)
      intermissionTimer()
      wait(0)
      displayGamemode()
      wait(5)
      mapSelection()
      wait(5)
      teleportAllPlayers()
      wait(0)
      startingTimer()
      wait(0)
      roundTimer()
      wait(0)
      roundEnded()
      wait(0)
      teleportAlivePlayers()
      wait(0)
      mapDestroy()
      wait(0)
      showResults()	
   end
end

Problem #1: Notifications

StarterGui is basically where the guis get cloned from, it doesn't change everyone's guis. So, instead, you make a function, right at the start that you call whenever you want to change text:

function notification(text)
	for _,v in pairs (game.Players:GetChildren())
		local find = v.PlayerGui:FindFirstChild("ScreenGui")
		if find then
			find.Frame.TextLabel.Text = text
		end
	end
end

-- to call it: notification("your text here")

Problem #2: Map

It should work, I see no problems. It is most likely something before the map function has errored.

Problem #3: Teleporting

The problem is that MapChosen is a local inside the MapSelection function, which means it doesn't exist inside TeleportPlayers().

To fix this, I would recommend you just create a local right at the start of the script, on Line 2 or something, called "CurrentMap". When it chooses the map, it sets CurrentMap to MapChosen, so inside the MapSelection function:

CurrentMap = MapChosen

This will mean you can get the current map in the entire script.

Also, here are some things to fix:

1. Make WaitForPlayers() a while loop, so:

function WaitForPlayers()
	while game.Players.NumPlayers < 2 do
		notification("You need 1 more player to start the game.")
	end
end

2. IntermissionTime() needs an end under the for loop.

Hope I helped :)