how can i make a multi round system?

So im making a game where the intermission begins in 20 seconds and then the game starts and lasts till 180 seconds, each round takes 20 seconds , after the beginning of the round all the players get teleported in the middle of the map.but idk how to make it more rounds in a game so there will be another gui with countdown for round and i also dont know how to make the game the end if there are no more players left , so the game doesnt play itself.Pls helppppp i cant solve this problem :( here is the script for intermission countdown , teleport players and round countdown all in serverscriptservice except the local script from the timer(gui that shows the intermission countdown and round countdown):

script from serverscriptservice:

local roundLenght = 140

local intermissionLenght = 20

local InRound = game.ReplicatedStorage.InRound

local Status = game.ReplicatedStorage.Status

local LobbySpawn = game.Workspace.LobbySpawn

local GameAreaSpawn = game.Workspace.GameAreaSpawn

InRound.Changed:Connect(function()

	if InRound.Value == true then

		for _, player in pairs(game.Players:GetChildren()) do

			local char = player.Character

			char.HumanoidRootPart.CFrame = GameAreaSpawn.CFrame
			
		end
	else
	for _, player in pairs(game.Players:GetChildren()) do

			local char = player.Character

			char.HumanoidRootPart.CFrame = LobbySpawn.CFrame

		end
	end			
end)

local function roundTimer()

	while wait() do

		for i = intermissionLenght, 1, -1 do

			InRound.Value = false

			wait(1)

			Status.Value ="Intermission: ".. i .." seconds left!"

		end

		for i = roundLenght, 1, -1 do

			InRound.Value = true

			wait(1)

			Status.Value = "Game: ".. i .." seconds left!"

		end
	end
end
spawn(roundTimer)

--script from the timer gui:

local Status = game.ReplicatedStorage.Status
local TimerDisplay = script.Parent.TimerDisplay

Status.Changed:Connect(function()

	TimerDisplay.Text = Status.Value

end)



--pls help me , i would really appreciate that