Henry, I had hens for eggs. I kept 6 and they were like pets. I would still keep them, but we built a house on the land where we used to keep them and no room now. As others mentioned, you need a secure hen house to house them at night. My hens were loose during the day to free range in the huge garden we used to have. I purchased my chicks at a feed store and they were not fully fledged. They had to stay in large box with a light on to keep warm. You feed them chicken feed which you can purcase at the feed store as well. They need to eat gravel too and fresh water too. And straw to roost on. Be prepared to muck their stalls - they poop a lot! It's all good though because it's an excellent fertilizer and be added to compost for the garden. I think they were about 4-5 months old when they started to lay. You don't need a rooster for eggs, only if you want baby chicks. Roosters can be mean!
Also, if they do not free range, they will quickly remove every blade of grass from their enclosure. It can get rather nasty and muddy.