I would like to setup a VPN server on my router. I have no idea how this works.
Does that allow me to access the connection remotely from a public hotspot? Or is it only for the devices on my network?

I did setup a client using OpenVPN, but I think I figured out that won't work unless I have a VPN service - which I do not.

I found some instructions on setting up a server using the PPPT setup. Is that the way it is done if I have a cable connection?