How can I make a objectives GUI that holds multiple objective texts?

I want to make it to where I only have one GUI that holds multiple texts for the objectives. For instance, let's say a player touches a part or initiates an event. When that GUI receives that command from whatever the player did, I want the GUI to display some text. Now let's say the player does something else. When the GUI receives whatever the player did again, it changes the text into another group of text that's been stored inside of a script inside the GUI.

I want to do this because I think it would be very efficient to have all the text inside one GUI, rather than multiple GUI's holding those texts.

I don't have any code because I'm starting from scratch. Any help?