So you're getting chicks? If so, get some chick starter feed from a livestock supply store. It doesn't really matter the brand of feed, as long as it seems fresh and is correct for you birds' age. I personally would recommend medicated chick feed (it contains amprolium, which helps prevent a common and serious disease known as Coccidiosis), but if you want, you can get a non-medicated feed.
If you want, you can start giving your chicks treats (mealworms, pieces of lettuce, fruit, etc.) once they reach about 4 weeks of age. But be sure to get them some chick/cage bird grit so that they can digest this tougher food.
Feed your chicks starter feed until they reach about 8 weeks of age. Then, if your feed store has grower feed, switch them to that. If you can't get grower feed, simply continue feeding starter feed. Once your chickens begin laying, or reach at least 18 week of age, you can switch to layer feed. At this point, you can also start providing extra calcium in the form of oyster shell or crushed/ground egg shells.