If you get an "access denied" message, that means that you need root
privileges to access the folder; type "sudo nautilus" or "sudo pcmanfm" into
the terminal and then your password and the file manager will open with root
privileges, which will allow you to change system folders so be careful and
make sure you know what you're doing!
I like to make a habit out of doing a dry run of opening configuration files,
locating the correct folder, etc. with a user account and read-only access
just to be on the safe side.
Your description of your training and educational methods sound exactly like
my own. I refuse to let people label me "self-educated" or "self-taught"
because I consider it an insult to the many kind people who have contributed
20 minutes or so of their time to explain unfamiliar terminology, encourage
me to experiment, and teach me how to teach myself since 2004.
What you are doing is admirable, achievable, and exactly what the pioneers of
the free software movement wanted people to be able to do.
You are very good at tech. You are doing everything right. T
Now, you've found the folder and copied it into one of your 500 gig drives,
right? You've backed up all of your personal files? You've got the Apple to
get online if anything goes wrong and you need to look something up or ask
Are there any other settings you want to keep? Any other data that needs to
be saved before the fresh install?