The elevator pitch for the Culture (the society the books are based around) is that it's a hyper advanced society governed/managed by Culture Minds (equally hyper advanced AIs) that are powerful enough to pay individual attention to each and every citizen. Citizens are just being sentient enough that call themselves "Culture citizens".
There's no centralized power stricture, or even a clear definition of what counts as Culture or not. If a certain society within the Culture thinks their ideals drifted too much, they can just pack up and declare "independence".
For individual citizens, they can pretty much do anything if they can convince someone (and only if they need resources). If they think it's not really a utopia, they're free to leave and join another society.
Most of the conflicts in the book happen because, in contrast to the Federation in Star Trek, the Culture actively tries to "improve" other civilizations they have a fundamental disagreement with, and how they try to not screw it up when there are equally powerful civilizations on the other side of the ideological divide.
So while you don't get the story of how the Culture came to be, you do see it contrasted with a bunch of societies they try to improve.