[jshier]

Yeah, 100 Days of Swift is actually an introduction to UIKit, not the Swift language (aside from the first 10 days or so), so anyone starting fresh should do the SwiftUI version. I do wish Paul (or anyone) would write a good intro to Swift the language without any of Apple's frameworks.

[lockhouse]

Apple has a really good first party book about the Swift language.

https://www.swift.org/documentation/

[runjake]

Paul has many, many videos focused on just Swift, the language. I’d post links but I am on mobile. The “Swift In One Hour” video is good along with his few multi-hour series.