You likely should look into the XML object.
It can contain your dialogs as well as sub "actions" like what button to display, and you can get how many lines are planned in a dialog, or even a precise response.
The trick is that you have to make your own structure for the XML file. It is possibly advanced stuff indeed, and not that accessible to a beginner (I don't know what's your user level at the moment).
I've been asked to do a video for the C2academy that deals with making a RPG dialog system, and I'll make my best to deliver before the end of July. Stay tuned on the playlist.