I’ve been following Paul Hudson’s work for a few years now, and I’m also a very happy subscriber to his Hacking with Swift+ program. Paul provides great learning resources, many of them for free. If you want to get started learning Swift (and SwiftUI), I recommend 100 Days of SwiftUI, his free learning program. He also has a UIKit version, at 100 Days of Swift.
But right now, around WWDC2022, he’s also running specials on his books and bundles, for 50% off.
I have enjoyed and learned a lot from his books, and own all of his bundles. It’s amazing how he keeps updating the various books. I really don’t know how he does it all. Hopefully I’ll get a chance to meet him and thank him personally at (or around) WWDC this year.