I started with this article on the initial setup, but skipped wireless and went LAN. https://makezine.com/projects/raspberry-pi-plex-server/
Screwed around to figure out the permissions and finally got that solved I thought, but when I go to add the files, I get nothing.
Pi is the owner, and is set as the user for Plex in /etc/default/plexmediaserver.prev. I’m not sure what to do next.