Welcome to the site, Evariate! :)
The variant creation guide that Yoshimon linked to, is indeed written by me and should cover the basics of variant creation. After that, you can indeed play the variant with your friends. And not only you and your friends could play the variant then; we would all be able to, and we will if we like it! :)
You are not dumb for not knowing how to contact Oli; I was purposefully vague about that in the guide. Oli is the site admin, but also a user, and you can search for him under Help => Find a user. But I would not worry about contacting Oli until after you have created the map(s) and are at a stage where you are ready for Oli to give you access to DevTools.
Sky_Hopper is wrong; that is not how things work. The Variant Development Thread he spoke about can be used to ask the vDip community for feedback on your variants, though. You can find the thread if you scroll a bit through the forum.
Please let us know if you have any more questions. If there is anything unclear in my guide, I'd certainly like to know.
Lastly, I would recommend to not underestimate the time investment in creating a variant. You will probably need quite some time to balance your variant (you can ask us for feedback on balance of your variant in the Variant Creation Thread if you would like that) and if you want your variant to look nice, you will likely spend quite some time on drawing, too.