It’s not required to follow along using the Twenty Nineteen theme, unless you’re interested in creating a site that looks like our demonstration site.
Most of the WordPress 101 tutorials deal with the features of WordPress itself, not the specific theme. So, you’ll find that the training you get from our video tutorials is more theme-agnostic than, “How to build this exact site.”
The next two versions of WordPress will include some significant new features, so we’ve opted to hold off on re-recording the entire 34-part series until the next version is released. Until then, you’ll find that the concepts and skills you learn in our WordPress 101 course still apply, no matter what theme you choose.
Hope this helps!