I really loved Stacy’s Photo Freedom book and class - I still have my family’s Library of Memories organized based on what I learned from her!
I’ve taken a ton of online classes related to scrapbooking, but many (most?) of the courses are no longer available.
Jessica Sprague has a great set of courses that teach you the technical side of how to scrap with Photoshop.
I learned a ton from Tiffany Emmanuel nee Tillman with her Scrapaneer’s courses and membership. Unfortunately, they’re no longer available.
And Cathy Zielske’s courses were fantastic for inspiration about what to scrap, not so much the technical end of it. But I still periodically look back through the materials from her Design class.