Although there have been entire books written about keeping chickens, they are incredibly easy to keep.
They need an enclosed run that can be made predator proof. You really don’t want them wandering your yard. There are those who claim that a chicken will not be destructive; in my experience they are mistaken. Chickens scratch and scratching rips up everything. They also eat plants. The reason you can use them as a chicken tractor is because they will turn the soil for you. They also leave their manure everywhere. You probably don’t want them hanging out in your yard – hence the enclosure.
They need a place to roost at night, although it need not be a coop. As long as they can stay warm enough outside, and fairly dry, they don’t need a building.
It is nice if they have nest boxes, but the fact that they have them does not mean that they will use them. They usually do, but you may find eggs anywhere in the chicken pen.
They need to be fed regularly. You can raise chickens entirely on kitchen scraps and what they can forage, if you have enough. Chickens did that for millennium before commercially produced chicken food became available. You can also give them grain and Black Soldier Fly (BSF) larva to round out their diet. Chickens love BSF larva.
They need grit for their crops in order to be able to digest their food.
And they need unlimited access to fresh, clean water.
If you give them those things, they will give you eggs.