It rather looks like I've been swindled out of my money. I gave up at that point, cursing Microsoft into eternity, and vowing to never use their products ever again.

Mine was a 1 PC/Mac version (onetime purchase) and I've a suspicion that the Microsoft server won't (or cannot) respond to a second attempt at installation, even though the app may be already eliminated from the user computer. I tried again a day later but got the same result. Since then, I've had another go at reinstalling Office, but this time the Microsoft server wouldn't accept my login password, even though it happily accepted the Product Key and my e-mail address. After nearly a day's work I concluded that there was simply no means of getting rid of OneDrive, it's compulsory it seems, so I decided to use Time Machine on my Mac to roll back to the pre-Office situation, getting rid of the Office account. I logged in at the account and deleted what I could, then returned to investigate the OneDrive interface on my Mac in some detail. From the security angle, this was the very opposite of what I wanted to have happen, as I use secure offline methods for storing all my files. However, I was utterly shocked to find that, after installing and activating, OneDrive was definitely running, and was actually copying every single personal/private file of mine from my entire system to the server! This was happening irrespective of whether I was signed in to the MS account or not. The trick then was to click on 'Install', not 'Standard Install'. I specifically didn't want those two, so I deselected them. This gave all the app's components to choose for installing, including OneNote and OneDrive. That's to say, when I got to the Install caption of the Setup, instead of gayly clicking on Install I selected the Customise button. I'm not sure if that's currently available also on your H & B version. And incidentally, in the setup process for the installation I found on my copy (as with my previous edition) that I could select/deselect various of Office's components. Initially, I had no problem in installing the app and then activating it. I recall also that you have to look in your e-mail inbox for a confirmation message from Microsoft. Don't know if yours is similar but with mine (the H & S version) you have to sign in to the MS account in order to manage it, and there's a setting for that on the Office menu bar at top of screen. I too recently purchased much the same retail version of MS Office for Mac2019 - at enormous expense I might add, reckoning that, once installed, it'd probably serve me well for around three years minimum.

Open office for mac 10.11.6