Where is the guestbook database?

I want to know where the database for the guestbook is, you know...the file with all the guestbook entries in it? I want to back it up so I will have a copy should anything unfortunate happen, but I looked through all the guestbook folders on my server and I don't see it.

Database is above root on your server. you should be able to access it from your online admin panel supplied with your hosting. Use SQL and you should be able to copy and paste all entries onto a seperate file.

I don't get it, can I access this root thing in my FTP menu? I've searched through all the folders on FTP and in the admin cpanel menu with my browser and I can't find it.

No, you will have to use phpmyadmin from the C-panel
You will find it in the database or MySQL section.
Also some c-panels have a backup feature, there you can backup the complete site our just your databases.