Unity Multiplayer Game Hosting

Hi there, I have access to a dedicated server and can do pretty much anything I want with it so I have that covered. My question is, how would I go about creating a game that I can host on there. I am wanting to create multiplayer games in the future but as a start I just want to create a very basic game, just people can join in and walk around. Any help towards making this happen would be greatly appreciated.

Thanks, Luke