No development knowledge is required to understand this book. The only languages you will see are declarative languages such as JSON or YAML. In addition to this, no specific IDE is required. If you do not have one, you can use Visual Studio Code, which is free and cross-platform. It is available here: https://code.visualstudio.com/.
As regards the operating systems you will need, there are no real prerequisites. Most of the tools we will use are cross-platform and compatible with Windows, Linux, and macOS. Their installations will be detailed in their respective chapters.
The cloud provider that serves as an example in this book is Microsoft Azure. If you don't have a subscription, you can create a free account here: https://azure.microsoft.com/en-us/free/.