Any open VPN protocol that MacOS supports will work. I'd actually say, you're better off not using something like Hamachi. Keep in mind, allowing your friend direct VPN access to your network without any extra rules will allow them full access to everything on your network, so make sure you only allow traffic to things you want them to access.

Check if your router already has a VPN Server you can enable and let your friend connect to and set it up (easiest option). If not, just run the VPN server on your machine, and forward the port from your router to your machine.