For a simple openVPN set up I've used https://github.com/Nyr/openvpn-install with quite a lot of success. It's handy that it let's you add multiple users if you're using it in a commercial setting too.
I use this as well on DigitalOcean. It's easy to create new certs and put them on my various devices so I can disable if I need to. I'll have to check out some of the other ones listed here but I've been using it for a few years now without any issues.