Ask HN: Learning Swift as an Existing Programmer?

It's been a while since I've had to learn a new language & stack from scratch. What are some good resources for learning Swift as an existing developer? There are a ton of courses online for non-programmers, but I don't want to learn what a print statement or conditional is. Instead, I want to learn how modern UI toolkits are used, how network calls are handled, best practices for async, multi-threading, error handling, etc. Real business logic stuff. Are there any courses like that, free or paid?

I'm a web dev, mostly frontend, who just wants to make a macOS desktop app for fun. I know most of app development is on iOS these days, but I don't particularly like that platform and would rather focus on the desktop, if there's a difference. I've previously learned React, JS, PHP, Perl, and Visual Basic.

Not really interested in React Native or other similar JS-to-native frameworks. I want to make a lean, fast, simple and unbloated app with native look & feel.