I tried earlier today and I had no luck actually getting an instance running
It would help if the explanation was specific to a raspberry pi
You could set up a dns based ad-blocker like pihole and a vpn like wireguard to tunnel your phone back into your home network so you have ad-blocking on the go, too. That’s a semi beginner protect with plenty of tutorials to pick from.
You could run nextcloud, syncthing, or immich to make your own cloud at home but that might need more than a basic pi setup.