Trevtassie

It's better if you educate yourself about moiney and how it is created and circulates. But what can be said is that the proportion of "self made" billionaires is pretty low. They are prominent in the media and popular culture, because it gives us all hope that "there but for a bit of bad luck" go I, and who doesn't like a good luck story. The reality is most really wealthy people have had a good start in life, and that an average person has the deck stacked against them as they don't have access to the networks that enable them to leverage what assets (whether financial or intellectual) they have. Things have improved with the rise of the computer age I'll grant you, have a clever idea, meet the right people at the right time and you might get lucky.
And no I don't know any extremely wealthy currently since I don't have access to the world they circulate in, which is part of why I will never likely be upwardly mobile financially. I once did know a Greek shipping billionaire who was married to my then partners sister, but only saw them once a year when they came to our city for a yacht race. They slummed it at the best hotel in town. Of course compared to the vast majority of the worlds population I'm filthy rich, but not among my peers.
In terms of how the financial system works, pretty well any book by Satyajit Das is a good place to start, I can recommend Masters of the Universe and the Cult of Risk. Debt: The First 5000 years by David Graeber is another good place to start. How money is created is a fascinating topic, especially once you realize the government and (in the US case) the Fed have only a peripheral role in the whole process.