I have been Backyard Chickin-ing for about 8 years.
Very rewarding.
I would check your your local municipality about needed setback regulations for coop & run . Some have restrictions against Roosters.
Check out
www.BackYardChickens.com for more info than you will ever need (It is Pelican for chicken farmers ... LOL)
Unless you want to raise chicks (I didnt because my children are old and gone ..but that is a great process for younger kids to experience)
Buy pullets (coop ready chickens)
They are sexed (so no accidental roosters)
They are ready to put in a coup (no heat lamps , special treatment)
They go right into regular feeding (no starter feed/ chick feed)
Find a way to build an automatic feeder ... Mine feeds 5 chickens for over 14 days
Build an AUTOMATIC water system. (mine are cups feed by a 5 gallon bucket that I have a toilet valve hard plumed to a water system.
Be aware of predators . I have never had an issue and my girls free range all day every day.
Decide
now about what you will do when they get sick. Will you use basic low tech methods to remedy an issue or take it to a vet (don't laugh ... my vet sees a lot of chickens). and when they stop laying do they stay as guests or "go away"? If you have to get rid of one (sickness or health ) can you do that (how will you do that)
Remember that laying chickens are NOT good eating !.
That is what is used as a "Fryer" in lower quality restaurants.
I have so many eggs I do make a lot of friends (often a 12 pack is a raffle prize at my weekly PCA breakfast). I pickle them, & egg salad is a regular (Please note fresh eggs do not make the best hard boiled eggs !) They are so fresh the membranes don't want to release from the shell. There are some tricks and things you can do for hard boiled.