move location of notifications from upper right to my 1st or 3rd monitor?

I agree with you completely -- there should be a way to tell it where on the screen makes it interfere the least with how you want to use your Mac system. This limitation has been complained about for quite a while and Apple has still not given users a way to do something about it, nor has any third-party app come up with a solution.

At least with a multi-monitor setup you have a choice as to what the primary monitor is. I tend to do most of my work on my non-primary monitor just for that reason (notifications interfere with everything).

Perhaps leave some feedback for Apple at https://www.apple.com/feedback/

Good luck...

You could also just disable notifications by setting "Do Not Disturb" mode in the System Preferences Notifications pane -- just set the time that do not disturb is enabled.

Good luck...

Perhaps try changing which of the monitors is the "Primary"?

Good luck...