I'm self-hosting an OpenVPN instance on a Digital Ocean droplet in Amsterdam. I built it from the ground up several years ago, looks WAY easier now.
Haven't used that particular doc, but what they had posted when I built mine was the clearest, most complete tech documentation I've ever followed. Big fan of Digital Ocean! Think I'm paying <$7/mo. for the server?
Not necessary, but if you want a domain name to point to karashta.whatever.name, NameCheap is my go-to registrar. Like Digital Ocean, cheap and comes with top-notch tech support.