Can I install discourse and ghost on the same server, if so any guidance I would be grateful
Yes, Discourse runs in Docker. Ghost can, too, albeit this is not the official method.
Check out the system requirements for each, and read their respectivee installation guides to determine is your VPS is the best way.
A typical way to run multiple containerized services on the same server is to install Nginx as a web server and use the reverse proxy feature of Nginx to proxy outside connections to services listening on ports on localhost.
Personally, I like installing Ghost using the official method of installing it directly on the server, so I might do that, and then install the Discourse “standalone” container that bundles all the Discourse dependencies into a single container.
Both Discourse and Ghost could then be proxied by Nginx.
Any installation steps?!
First, Install Ghost using the official instructions.
My suggestion is to use docker for both installation.