... and still learning my way around. 0.o

This Game is a good example for me, as it has multiple parts under "Extras".

When I install the game, do I have to go back to Extras, where DLCs, Patches are a-a-a-all listed there and Install them all myself?

They're all listed under Offline Backup Installers, in Extras

When I look underneath Manage Installation / Configure, the DLC's tab shows (at least it shows all the DLC content 'checked off'') or 'selected' so it LOOKs like the content is already enabled but unclear.
THEN what about all these patches, again listed beneath Offline Backup Installers?

As I began with - simply looking for some organizational directionals from you gurus out there lol. Thank you for any and all help. Seriously.

Are you using GoG Galaxy to manage and install the game and DLC's?

If you are, then yes, it will install and update all Game and DLC Files. The Extras, you can install on your own.

If you are not using GoG Galaxy to manage or install the game, then you will need to download all game and DLC offline files and install them manually.

The patch files are only installed by you, if needed by you the user, once an update comes out that is a newer version then the full install game version. If using GoG Galaxy, the game will auto update all game files, if you have those setting checked.

tyvm!!