Maybe update the documentation to make it clear how to find this in a new installation as I’m assuming people like me who just downloaded the app and never used it before are the target audience here.
You’ve downloaded a really old version of Unity. The tutorial you’re referencing is “checked with version 2017.3”, while you’ve downloaded 5.4 (says so in the toolbar), which is well over two years old. They hadn’t made the Learn section of the Unity launcher back then, that’s a pretty recent addition.
If you grab the latest version from here, you should be good. To be completely sure that everything matches the tutorial, you can get 2017.3 from here.