I took a look at the tutorial and I saw nothing in it that requires macOS 13.
Can you clarify what you were doing when you got the error messages? Did the errors occur when you were typing code or when you build the project?
At that point in the tutorial, it says the previews won't work because of the new stuff you typed. The next section in the tutorial fixes the problem.
Topic:
UI Frameworks
SubTopic:
SwiftUI
Tags: