picture help.

This post by Terence Devlin is an excellent treatise on organizing photos with iPhoto: Better way to organize my images?: Apple Support Communities.

It's bound to give you good ideas on applying the concepts discussed to your own needs.

These user tips will help you make the transition from iPhoto to Photos and to organize photos in your Photos Library:

Notes on Migrating an iPhoto Library from iPhoto to Photos for Mac

• Moments in Photos are the New Events
• External Editors in Photos Are Here
• Post 9/30/2018 Printing Options for Photos - Apple Community
• Ordering Books and Calendars on a Mac that cannot be updated past El CapitanUse Project Extensions to order print products in Photos after September 30, 2018 - Apple Support
• Create and order print products in Photos with Project Extensions - Apple Support

As for duplicates you want an app that will identify the potential duplicates, put them in an album or mark them with a keyword for easy retrieval and deletion by you. You don't want one that does the deletion itself for obvious reasons.

I've run tests on the following apps with these results::

PhotoSweeper - $9.99 - Demo version available.

PowerPhotos - $29.95

PowerPhotos is the iPhoto Library Manager version for Photos and is very powerful. Although more expensive I would recommend it as it has more capabilities than the others like the capability to merge Photos libraries or copy photos along with their metadata between libraries.

PhotoSweeper compares bitmaps and/or histograms so it can detect duplicate images even if they have different sizes, file names, sizes and capture dates.