How Do I make Chat Gui Tips with the default chat Gui?

While the script in the commented link is a very interesting function, there's a built in function for making System Messages known as ChatMakeSystemMessage.

From that wiki page:

"The following code would say "Welcome to my game!" in the chat, colored cyan:"

game:GetService("StarterGui"):SetCore("ChatMakeSystemMessage",{
    Text = "Welcome to my game!"; -- Required. Has to be a string!
    Color = Color3.new(0,1,1); -- 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
    FontSize = Enum.FontSize.Size24; -- Optional, defaults to Enum.FontSize.Size18
})

Hope this helped.

The script Pyrondon suggested is functional and it works, but I'm guessing you might want messages over time, so what you can do is before line 1, insert a wait script, so if you wait(60) which is one minute, it will then display the message. I as well used this script from the roblox wiki, and made multiple local scripts in the Starter Gui, then i just changed the wait time and the text for each one.