You are going to have to setup media structure exactly as pictured then each use have to register their own plex accpunt and you then setup selection for each user. Pain in the ass if you ask me.
Kinda.
I have one admin account that's the actual plex account.
I have a local account for each of the 4 peeps in our family. This acts just like an external account, but
can't access the Plex server remotely. But it's handy so my wife can keep track of local content she likes, while I do too, and kiddos also.
I played around with parental controls for my younger son, and was able to block mature content pretty easily. But, still gotta parent him a little cuz he figured out pretty quick to just login to moms account and watch whatever. 😂
My admin account is the actual plex account, locked down with 2fa and locally PIN.
But if you want users access remotely, then yes....gotta have a plex account for each user. Invite that user, and manage their permissions.
Setting up the folder structure is crucial for any streaming service, as is file naming (and tag data for music).
It's definitely not overwhelming if you get it setup "right".
The OP's folder structure looks a little wonky, but I'm not very familiar with emby to that level, and I dunno what OS he's using.
edit: clarity