The two I can think off of the top of my head are Paul Hudson's web site <a href="https://www.hackingwithswift.com" rel="nofollow noreferrer">https://www.hackingwithswift.com</a> and the old Ray Wenderlich site which is now called Kodeco <a href="https://www.kodeco.com/home" rel="nofollow noreferrer">https://www.kodeco.com/home</a>.<p>Another good resource is Standford's CS193p - Developing Applications for iOS using SwiftUI which is online at <a href="https://cs193p.sites.stanford.edu" rel="nofollow noreferrer">https://cs193p.sites.stanford.edu</a>.<p>Should be more than enough to get started.