AD is a huge area. It includes DNS, DHCP, NTP, Event Viewer, GPOs, Powershell and more.
On my blog I do offer a step by step guide with practical and information around tools and architecture including RFC standards.
Give him a piece of hardware and get him started. If you haven’t build a lab so far, try my guide that stats here: https://hartiga.de/windows-server/windows-server-2025-part-1-preparation/
All of it is made for beginners with animated gifs and evolves over time. It remains useful for someone doing homeautomation to develop a real world solution with personal benefits like AD blocking.