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)
As an extra step you can block DNS requests to external services from within your network to prevent devices trying to reach hardcoded for example Google DNS servers to bypass your filtering which isn’t uncommon with some IoT/streaming devices. Best to both block the known IPs as well as have DNS redirects for the urls that point back to your firewall at whatever IP it’s using to serve DNS from. There is a list called DoH servers by name or something like that which you can add to the blocklist to try and prevent usage of any DNS but your own.