There isn’t much to say about an old, outdated technical manual. There’s at least one newer edition of this book released. However, whether you’re using vim or neovim, the basics remain the same. If you only have access to this edition of the book, I would focus on the chapters that teach you how to use vi and vim. In that respect, this book is very well written. Ignore the chapter on plugins and scripts as those have evolved quite a bit (especially in neovim with their use of lua).