This is essentially a detailed Microeconomics textbook. Kirzner has great insight, but a lot you learn in Micro 101, although there are a few things in this book that I don't remember covering in micro like how detailed Kirzner is about the discovery process and how we reach equilibrium.
One thing that annoyed me about this book (and all other not textbooky textbooks) is the usage of visual displays. This book by Liberty Fund is a great book. The pages are great, cover is fine, but it's just that: a book. The build is not a textbook so having to flip back to a page to see the isoquant is super distracting sometimes. Overall, even though most you can learn in Micro 101, I still suggest this book because of the detailed work on the discover process, great work on equilibrium possibilities, and it's easily readable (when you don't have to look at all the graphs).