best way to display 35 mm slides on my Mac. Have hundreds of slides I would like to organize in Photos.

As was mentioned above... Run some searches, and see what's available.

Having discussed this with somebody locally a while back, acquiring a slide scanner and associated software, or have a local photo service with a (usually higher-end) slide scanner digitize them for you. The latter will cost you a little money, but it'll get you good scans and it'll avoid the one-at-a-time scanning involved with a low-end slide scanner, and which can be pretty tedious. And you won't end up with a slide scanner you don't need.

Software to correct the scanned images can include Adobe Photoshop, or Affinity Photo, or Acorn, or otherwise.

It's much less time consuming to view the slides themselves. Then only scan the ones you think are worth saving.

A simple, battery operated, hand held viewer works well. Like these. Or, a small LED light table with a decent power loupe. I still have my loupe like that from vo-tech. Nice that they stand on their own without covering much of what you're looking at.

The rather low cost of these items is worth it when you have a lot of slides to evaluate. Can also save you a fair amount of money if you have an outside service scan them, only to find afterwards a good percentage weren't worth scanning in the first place.

Digitize them.

https://www.google.com/search?client=firefox-b-1-d&q=digitize+35mm+slides