So, Ivan, what I'm getting here is that you're looking for more information about the "world" of D&D and what sort of NPCs (Non Player Characters) you might find there (and/or how character creation works, perhaps)?
Seems like a fairly simple question at it's core but, in reality, the answer(s) are faaaaar more complex than the question... soooooo.... where to start in even
attempting to answer, hmmmm?
I guess "the world" bit is the best place... the thing is, though, is that there isn't just a single "world" in D&D. There are numerous worlds or "campaign settings" in which adventures could be set, in fact. These various worlds range from those created by developers - see
The Forgotten Realms (this world was used for such video games as Icewind Dale, Baldur's Gate, and Neverwinter Nights) or
The World of Greyhawk, for example - to worlds/campaign settings created wholly by individuals or "user communities" like our own:
Audalis, for example, is the world/campaign setting created, initially, by our beloved webmaster and enhanced and expanded by more than a couple of our other Innmates here at the Inn. The world of Baelona, too, is a campaign setting created by, Tek, another of our Innmates, which is utilized in a number of games which have been run hereabouts... I've got a couple of my own, as well, but that's neither here nor there. The true point, here, is that "the world of D&D" can be just about anything you want it to be. D&D
isn't a world unto itself, you see, it's more a set of guidlines and structural templates that allows you to take a spark of imagination and kindle it into a raging conflagration of adventure and excitement.
I'll give you a bit of time to read up on the links I've provided you, here, and, after you've done that, and if you still feel up to it, I'll be more than happy to expand on my already longwinded lecture.
And, hey, if you've got a question or three in the meantime, don't hesitate to drop me a PM or something.