What is the scope of this article? Do you want to teach them the whole fundamentals of OOP, or just simply explain it to them in brief and let them do their own homework?
The transition between Lua -> C# isn’t that straight forward, there’s a lot of concepts to cover that don’t translate that clearly between an embedded scripting language like Lua and a strongly typed, object oriented and component-oriented language such a C#.
People already are strugging with Lua, now imagine teaching them how to transtition to C# and having to tell them “Hey actually, in C# you can’t assign a String to a float variable!”, they’d just look at you like a moron and say that Lua is better because it’s possible in Lua!
To be fair, I don’t think a text-based wiki tutorial is the way to go, instead, I’d recommend creating video tutorials aimed at people coming from Garry’s Mod Lua to S&box C#, teaching them the language there, the necessary concepts and so on, and the wiki post would be an index of all the good research material and tutorials they could use. I find that beginners learn much better visually rather than staring at a wall of text and code.
Like, link this to a green person:
And watch them turn pale - If this was a video, you would be able to break it down better bit by bit without necessarily holding their hand too much.
TLDR: Video tutorials and an wiki-page index aiming beginners at those tutorials and learning material is the way to go for me, personally.
EDIT: Of course, you could still create tutorial series for people who aren’t completely green to programming, how they’d use S&Box-specific concepts. For example, hooks in Garry’s Mod Lua, network library etc. are unique to Garry’s Mod, so naturally, showing how to interact with those systems to people that already know how to code would be beneficial.