I want to make a few points to help clarify some of the choices and why I made them. This is very helpful and I appreciate all the comments as it highlights how some things are clear in our head but we don't end up sharing that with anyone reading. So:
1. I looked at AdGuardHome but I preferred PiHole because I found its documentation a bit more helpful for my purpose (the Unbound sample, the Wireguard setup, etc)
2. I saw the docker compose package, but I wanted something that runs at the OS level. There are docker packages for Wireguard too and I had also a look at Mistborn (https://gitlab.com/cyber5k/mistborn)
3. The VPN is the main thing I wanted setup to reach resources on my home network, adblocking and DNS came a bit later, so you can run this without a VPN, but its central for my setup.
4. I really wanted this setup at the OS level and to hopefully learn more about the whole process.
Thanks again for the suggestions though!