Gentlemen thank you both for your kind help, it’s appreciated.
To give you a better understanding. I use to be a web developer and I occasionally make WordPress websites for clients, as and when they crop up. Which is why I have an old Plesk server hanging around. I wanted to try and squeeze this project onto it as well to save money, but I am more than happy to provision a new machine especially for this website, as it’s my own pet project. It will probably take a couple of years before it makes me any money, so I can’t afford any developer fees.
I’ve never set up a Discourse forum before, no one has ever asked me to do so. I’ve no intention of becoming a ‘Discord Developer’ This would be a one-off just for myself and six months from now I will have likely forgotten everything I did to set it up in the first place 
So any links are really appreciated.
Thanks very much.