Alright, this is my first time using Oxide plugins ... I am on a Nitrado Server, Oxide is pre-installed here already ... I downloaded Advert Messages and got a advertmessages.cs file ... I simply drop & drag this into /rust/oxide/plugins folder and that's it? I am using WinSCP btw ... is this how I install Oxides and how do I later configure them? ... I would appreciate your help :)

Yes, that is how you install plugins. If configuration is available, you can find a config file under oxide/config. For more info, see https://umod.org/documentation/getting-started

many thanks!