Using a spare or your desktop PC at home, install Hyper-V and start creating and breaking VMs using the Server trial ISOs. You can find info on AD DS Getting Started or MS Learn too. I am sure there are a ton of other resources too.
The books are typically designed to teach to to pass Microsoft exams which include AD as a subject matter. The advice to build a lab and experiment is very good advice.
Here are the basic docs, if you want them. There is some good info, but keep in mind that there is a world of possibility you’re not going to realize until you just do it. https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/ad-ds-getting-started