Have you gotten it working with just those steps? Every single tutorial we have tried on our work machines have resulted in failure with Ubuntu 18.04. I can usually get to a login prompt but then logging in just gives me a black screen, or other times the login is always rejected.
VNC works, but is so painfully antiquated in comparison to RDP. It guzzles way too much bandwidth even if all you have is a blinking cursor on screen. I really wish there was a solid RDP server for Ubuntu. I'm quite surprised at the state of things on this front.