I want to block ads and trackers on the whole home network. I’ve been using adblockers and trackers for years now; I currently have a Raspberry Pi. I was thinking of setting up Pi-Hole with AdGuard. Any other suggestions are welcome. (I can’t use a custom router, because my ISP doesn’t allow it)
You can setup DHCP to give the DNS address to every device automatically. Even heavily locked down routers sometimes have the option, but I guess OP will have to try that out.
Pihole also has a built in DHCP, which you can enable and use as long as you disable the router one.