I can share my experience from last 2 weeks, first went through Apple Tutorial https://developer.apple.com/tutorials/swiftui/ for the what's. It is very well written and suits its purpose .... However if you want to understand the why's, Apple Architecture etc definitely recommend as well Paul Hegarty Stanford CS193p it was an eye opener for me to understand architecture, design pattern, struct vs class etc it accelerated my understanding 10x. Good luck and have fun !