Is hacking with swift, 100 days of swiftui aimed at beginners? I ask because the posts on the forum and indeed the level of progression in the course is beyond me. As with all the online tutorials I've come across there is no feed back loop, i.e a real beginner being coached in realtime using the course material.

It depends a lot on what you mean by, "beginner." It's not going to teach you how to program. It will teach you how to program in Swift and how to use the features of SwiftUI if you already know how to write programs in some other language and have never looked at Swift before.

And if you're really struggling with the basics of Swift, I highly recommend Paul's book, Hacking with Swift, since the first bit of the book covers language syntax and structures.

I suspected that it was for people who could already program. I haven't come across a course for complete beginners.

I'd suggest Udemy or Coursera, look for a beginning CS class, intro to programming. It'll probably be with something scripty like Python, since the point is to learn how to organize your thoughts and use the basic language constructs rather than specific application development. Avoid courses with titles like, "Learn iOS Programming in 10 Weeks," or, "Building Great Websites with Javascipt and CSS."