This OpenVPN[0] setup works very well and uses certificates for auth. It's easy to use and you just need to set up port forwarding in your home network so you can dial in from remote.

These days all the cool kids are using WireGuard[1] though. I don't have a link to a handy installer and setup guide for that but they do exist.

Using a Pi 4 with gigabit ethernet makes a big difference over older Pi hardware.

[0] https://github.com/Nyr/openvpn-install

[1] https://www.wireguard.com/