How Do I Get My iPhoto Images Back?

iphoto is no longer available,I have several projects that have quite a few projects with retouched images. I have access to the completed photo books, but not the actual images. images were set up in folders with raw and retouched images, I can’t find any of them.
if I do a search, nothing comes up. I am currently running EL Capitan 10.11.6.
Any help would be greatly appreciated, I would hate to think I lost all those images, it was a lot of work.
Also, on a side note, I have images that are in photos. They were downloaded from a digital camera. How do I access them to work on them in photoshop, and then save them for future projects
Thank you in advance
Rita
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Rita