For our common understanding let's first review some basic definitions.VPN = Virtual Private Network
- a network consist of at least two machines.
- private means that these two machines are setup to confidentially understand each other.
- virtual means that this private understanding can go over the public internet.
I understand that you want to setup one
machine for VPN.
Are the second (or any more) machine(s) under your control, so that you can set them up to understand VPN requests of your FreeBSD machine? In this case, you can connect these machines over the internet into a VPN.
Or, did you receive any VPN connection credentials from anyone? In this case you can setup your FreeBSD system to connect over the internet into that particular VPN.
Zero configuration VPN does not exist, so there is no way to connect a single VPN setup without additional efforts to anything in the internet.