permission denied while backing up from install drive start-up

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P.P.S. Sorry...

In case the hangup at the login screen from my previous post is a partial hard drive failure, I'm at least trying to back everything up because I haven't done that in a while. But the external drive I'm trying to back up to is actually the hard drive from an old Toshiba laptop that I don't use anymore, and I'm wondering if I should try to put it into my current computer, a Thinkpad T61, to replace the potentially partially failing hard drive. Any thoughts about that are also welcome. I found this article which looks useful for that, but I'm not clear which way I should go with this: https://www.howtogeek.com/442101/how-to-move-your-linux-home-directory-to-another-hard-drive/

[betwixt]

P.S. the aforementioned "linux" directory is at /media/linux and my home directory is, according to file manager, in directory with a long complicated name consisting of a bunch of numbers and letters, but copying the directory location manually into terminal only returns a "no such" error.

[betwixt]

I'm using linux lite from the flash drive that I originally installed with (because of continued problems logging in, per my previous post), and I'm trying to copy my entire home directory to an external hard drive, but many files and folders show up in file manager with an x, and when I try to copy them, I get a message saying "permission denied." So I tried doing it through terminal (I'm a beginner, but I know the basics), and I can't figure out how to access the home folder. It recognizes a parent folder called "linux," which, when I look in file manager, contains my home folder, but when I try to navigate to that with 'cd' in terminal, it doesn't exist.

Please help! Thanks for considering,
Arbor