Hi Anni D, I'll have a go at this! (starter for 10)
Food - pellets or crumble, both good. (Smallholder range a favorite here)
Grit - usually comes as mixed grit with oyster shell. But if they are scratching and foraging in open soil then will get enough anyway so less important (they must have grit from somewhere)
Bowls or feeders - inc a water bowl or two. Bowls or hoppers need to be raised off the ground by a couple of inches - chickens kick bedding, soil, anything around into food and water with remarkable efficency! But not too high either, it's a ballance.
Auboise or shavings for covered runs (when not on grass) and nesting box. Auboise is really good stuff.
Some mealworms, sunflower seeds (not in shells), grapes, for bribery! But not more than 5% of daily food. They need their pellets however much they try to convince you otherwise!
Greens (various mostly brassica) - as much as they want.
No long grass or potato peel!
A dust bath (basically soil in a tub) - If they can't make there own.
All sorts of other stuff (mostly first aid and supplements) but some vasiline for combs in very cold weather is number one.
A good pan for all the eggs your going to get!

(I presumed they were point-of-lay or older. Young pullets/chicks have other needs)