How should I best setup / use Photos? – Info Mac

Hi. New to Mac and trying to understand how best to setup and use Photos.

I have an external HDD with a ton of photos/videos. I also have photos/videos on iCloud (some overlap but not much in the last 18 months).

Previously I used Google Photos to download/import and manage photos locally. As part of the switch to Mac, I want to use Photos to manage all of my photos.

I do not want all the photos on the external drive also on iCloud (I don’t want to pay for the extra iCloud storage).

I’d also like to be able to download / save photos from iCloud photos to my external HDD. I like the idea of saving images as a means of backup, but am open to alternate means to meet the goal of keeping these precious memories safe. (I have time machine up and running along with backblaze for offline storage)

Is this something that can actually be done? If this best done via multiple photo libraries (local and iCloud)? Or just download iCloud photos manually and keep all things in a single library? Or should I just use another photo manager software package?