Familiarity with Angular 2.0 or greater is a plus but is not required
The screenshots in this book are taken on a macOS. There would be little difference (if any) for users of any other OS. The code samples, however, would run without any discrepancies irrespective of the OS. Anywhere we have CMD/cmd/command specified, please use CTRL/ctrl/control key on the windows counterpart. If you see return, please use Enter and if you see the term terminal/Terminal please use its equivalent command prompt on windows.
In this book, the code base is built incrementally as the topic progresses. So, when you compare the beginning of a code sample with the code base in GitHub, be aware that the GitHub code is the final form of the topic or the example that you are referring to.