If we turn to A FEW NOTES ON THE CULTURE by Iain M Banks, we get a pretty decent overview of the life (and death) of an ordinary Culture citizen.
In short, they party, they have hobbies that entertain them for weeks or a lifetime (like the games seen in Player of Games) or until they get bored, they attend cultural events (like the concert seen in Look to Windward), they travel, they partake all kinds of weird and wonderful artificial environments, they spend a considerable amount of time blissed out of their heads on glanded drugs (at least in their youths) as well as fornicating with anything and everything that moves.
Unless they don't want to. Gestra Ishmethit, for example, spend his entire life hating the Cultural lifestyle and ended up living as a hermit on a Rock.
Briefly, nothing and nobody in the Culture is exploited. It is essentially an automated civilisation in its manufacturing processes, with human labour restricted to something indistinguishable from play, or a hobby.
No machine is exploited, either; the idea here being that any job can be automated in such a way as to ensure that it can be done by a machine well below the level of potential consciousness; what to us would be a stunningly sophisticated computer running a factory (for example) would be looked on by the Culture's AIs as a glorified calculator, and no more exploited than an insect is exploited when it pollinates a fruit tree a human later eats a fruit from.
Where intelligent supervision of a manufacturing or maintenance operation is required, the intellectual challenge involved (and the relative lightness of the effort required) would make such supervision rewarding and enjoyable, whether for human or machine. The precise degree of supervision required can be adjusted to a level which satisfies the demand for it arising from the nature of the civilisation's members. People - and, I'd argue, the sort of conscious machines which would happily cooperate with them - hate to feel exploited, but they also hate to feel useless. One of the most important tasks in setting up and running a stable and internally content civilisation is finding an acceptable balance between the desire for freedom of choice in one's actions (and the freedom from mortal fear in one's life) and the need to feel that even in a society so self-correctingly Utopian one is still contributing something. Philosophy matters, here, and sound education.
Education in the Culture is something that never ends; it may be at its most intense in the first tenth or so of an individual's life, but it goes on until death (another subject we'll return to). To live in the Culture is to live in a fundamentally rational civilisation (this may preclude the human species from ever achieving something similar; our history is, arguably, not encouraging in this regard). The Culture is quite self-consciously rational, sceptical, and materialist. Everything matters, and nothing does. Vast though the Culture may be - thirty trillion people, scattered fairly evenly through the galaxy - it is thinly spread, exists for now solely in this one galaxy, and has only been around for an eyeblink, compared to the life of the universe. There is life, and enjoyment, but what of it? Most matter is not animate, most that is animate is not sentient, and the ferocity of evolution pre-sentience (and, too often, post-sentience) has filled uncountable lives with pain and suffering. And even universes die, eventually. (Though we'll come back to that, too.)
In the midst of this, the average Culture person - human or machine - knows that they are lucky to be where they are when they are. Part of their education, both initially and continually, comprises the understanding that beings less fortunate - though no less intellectually or morally worthy - than themselves have suffered and, elsewhere, are still suffering. For the Culture to continue without terminal decadence, the point needs to be made, regularly, that its easy hedonism is not some ground-state of nature, but something desirable, assiduously worked for in the past, not necessarily easily attained, and requiring appreciation and maintenance both in the present and the future.
We do see a fair few of the "little people" in the books.
Player of Games.
Yay Meristinoux is busy designing mountains for her home orbital. She's frustrated because they won't let her design entire plates. She spends her spare time having casual sex, going to parties, running naked in the rain and playing a variety of board games and live-action gun games. Gurgeh's unnamed (lady)friend is keen on casting iron, having graduated from 'pokers and fire grates' to the cannon she presented him with as a gift. Professor Boruelal evidently runs a university course specialising in game theory and practice (and has various adult students).
Use of Weapons.
Zakalwe goes on a tour of the (Contact-affiliated) GSV Size Isn’t Everything. During his time he meets a middle-aged man who's waiting tables in a restaurant, having taken time off from his day job cataloguing alien religions. Another resident is busily building a GCU with a team of friends. She acknowledges that it's both purposeful and pointless at the same time, undertaken for personal enjoyment and self-satisfaction.
Look to Windward
Ambassador Kabe is busily recording the mores of the Culture citizens that live near to him. They party (as Kabe notes, endlessly), play music, make fine jewellery, attend concerts and sports events as well as flying light aircraft, riding the lava rapids and glacier caving.
“Well, yes, and why not? They socialize, they have work-hobbies, they
play in more gentle forms, they read or watch screen, they go to
entertainments. They sit around grinning in one of their glanded drug
states, they study, they spend time traveling—”
“—apparently just for the sake of it or they simply … potter. And of
course many of them indulge in arts and crafts.” Kabe made a smile and
spread his three hands. “A few even compose music.”
“They spend time. That’s just it. They spend time traveling. The time
weighs heavily on them because they lack any context, any valid
framework for their lives. They persist in hoping that something they
think they’ll find in the place they’re heading for will somehow
provide them with a fulfilment they feel certain they deserve and yet
have never come close to experiencing.”