How do I make the script stop once it chats all the messages?

player = game.Players.LocalPlayer

while true do
wait (90)

local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = "[Server]: Hello, and welcome to Demure® Runway!"; -- Required. Has to be a string!
	Color = Color3.new(0,128,0); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSansBold; -- Optional, defaults to Enum.Font.SourceSansBold

})

while true do
wait(120)

local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = "[Server]: Join our group if you'd like to go through amazing experience!"; -- Required. Has to be a string!
	Color = Color3.new(0,128,0); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSansBold; -- Optional, defaults to Enum.Font.SourceSansBold

	
})

while true do
wait(70)

local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = "[Server]: If your catalog gets broken, be sure to spam click the 'R' button in the catalog."; -- Required. Has to be a string!
	Color = Color3.new(0,128,0); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSansBold; -- Optional, defaults to Enum.Font.SourceSansBold

	
})

while true do
wait(100)

local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = "[Server]: If you'd like to refresh, say 'refresh', or 'refresh me'."; -- Required. Has to be a string!
	Color = Color3.new(0,128,0); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSansBold; -- Optional, defaults to Enum.Font.SourceSansBold

	
})

while true do
wait(20)

local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = "[Server]: If you find any bugs/glitches, make sure to contact Ber_ries as soon as possible."; -- Required. Has to be a string!
	Color = Color3.new(0,128,0); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSansBold; -- Optional, defaults to Enum.Font.SourceSansBold
	
})

local levelevent 
levelevent.Event:connect(function()
		local StarterGui = game:GetService("StarterGui") -- Make sure this LOCAL SCRIPT is in StarterGui!
game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
	Text = " "..player.Name.." has level up!"; -- Required. Has to be a string!
	Color = Color3.new(1,1,1); -- Cyan is (0,255/255,255/255) -- Optional defaults to white: Color3.new(255/255, 255/255, 243/255)
	Font = Enum.Font.SourceSans; -- Optional, defaults to Enum.Font.SourceSansBold

})

end)
    end
        end
            end
                end
                    end

Basically, this scripts works perfectly. But once it's done saying all the messages, it's repeating them and I don't want it to repeat it.