Your current list of "blocklists" is located at: /etc/pihole/adlists.list
You can save this file and restore it when needed. after that you'd have to run a pihole -g to update local list.
Both whitelist and blacklist "lists" are located under /etc/pihole/whitelist.txt and /etc/pihole/blacklist.txt
If you're missing the files, that means that no whitelist or blacklist entries have been saved.
The newest version (in the works - currently in Beta ) of Pi-hole addresses that problem.
You can read this guide too on how to move the log file destination:
Due to the nature of file system access required for this type of operation, you'd have to remove the SD card and backup it in another device.
I recommended reading this article: