how to make minigames during rounds?

I watched a tutorial on how to make intermission and rounds that have a timer and tp players to lobby/game when the timer is over. My game is a game where once you spawn into the game area, disasters like volcanos and acid rain will happen. but with this script I cant figure out how to make those events start when players tp to the game area. My script:

local roundLength = 125
local intermissionLength = 35
local LobbySpawn = game.Workspace.LobbySpawn
local PlateSpawn = game.Workspace.PlateSpawn

local Status = game.ReplicatedStorage.Status
local InRound = game.ReplicatedStorage.InRound

InRound.Changed:Connect(function()
	wait (1)
	if InRound.Value == true then
		for _, players in pairs(game.Players:GetChildren()) do
			local char = players.Character
			char.HumanoidRootPart.CFrame = PlateSpawn.CFrame
		end
	else
		for _, players in pairs(game.Players:GetChildren()) do
			local char = players.Character
			char.HumanoidRootPart.CFrame = LobbySpawn.CFrame
	end
end

end)

local function roundTimer()
	while wait() do
		for i = intermissionLength,  1, -1 do
			InRound.Value = false
			wait (1)
			Status.Value = "Intermission: ".. i ..""
		end
		
		
		for i = roundLength, 1, -1 do
			InRound.Value = true
			wait (1)
			Status.Value = "Chaos: ".. i ..""
		end
		
		
	end
end
	spawn(roundTimer)