Yep James, even for a Mac user, you “got it”. (JUST KIDDING!)
Looking at your message again, I get the impression you are only talking about the My Passport Wireless, and not a My Cloud NAS – it is a different category of WD products, and the MPW is not a My Cloud product, although similar in many ways. There is even a special forum topic just for the MPW under external drive section.
Anyway, I want to clarify this comment of yours:
"— if I understand - I need to access the Wireless Passport through the computer . . ".
Yes, but not wirelessly. You need to use the supplied USB3 cable to directly connect the MPW to the computer as you would with any other external drive. Turn it off before you connect it, PC will power it up.
Whenever one does any kind of disk management on a drive it should be as a connected drive; not a wireless drive. Yes, I will send a photo or two to it wireless ly, but not much than a file or two.
So, when I got my MPW, I connected it to the PC this way, got to the root of the drive, created a main folder for My Media and in it, added subfolders for Music, Photos and Videos. In each folder I copied (from my PC, or another drive connected to PC at same time, etc.) the appropriate media types into the MPW subfolders. It was a lot of data, and I kept the MPW connected to PC for power once all copied and it did a lot of spinning as it created the large database on drive to catalog all the added files. So, be patient. Then, remove drive as you normally do. Turn on MPW, get your mobile device and check out your new media files on MPW using your My Cloud APP to access the MPW. Have fun…
If you don’t yet have it, you need the complete User Manual for the MPW, It explains about all this and other features and controls. Go to wdc.com, Support area, find the MPW and manual to download.