There is no doubt this is a good introduction to LoRa and LoRaWAN, and it covers a lot of the details of the protocol, it has several code snippets and refers to the author's github repository. It may require frequent update and new editions: for example the board Arduino MKR WAN 1300 is already replaced by the MKR WAN 1310.
Other than that, I recommend it to anyone wanting to start with LoRa and LoRaWAN!