I'm guessing that the book wants to restore your InDesign preferences before starting the exercises.
If that is true, here's a description of how to do that. Good luck!
Wit the Mac you have access to the Library if you type SHIFT+CMD+G (Go-Goto folder) then enter ~Library there you will find a folder with the name:
preferences/Adobe/InDesign/Version [a number]/[Language]
There are all your settings
Within InDesign you can go to: Windows - Utilities - Scripts
Right Click on the User-Folder then «reveal in Finder». Then you go back two folders an there you are again.
I save the directories en_US on a regular basis.
Did I get your question right?
Daniel (from Switzerland)
Hold down the alt key and go to the Finder, the Go-menu will now offer you your personal library. Without ALT-Key it is hidden.
your last post was blank. That happens with some email programs, in which case you need to come back to the web page to post.
Thanks so much for solving my problem. It worked and prevented me from getting more stressed out than normal.