Launch the Plex interface on your NAS. Opens a new browser window. Then on the left it should have libaries, (hover next to it) hit the plus to add one. Select media type (movies, tv, etc.) The next ...
Are you prepared to properly start a Plex server?
I recently bought a new Synology NAS and am still transitioning my data from my previous two units to it. It's about 30TB used on a 62TB volume. It's running on 1 GB Ethernet for now, but I'll ...