If you are just looking for eggs, you should get 2 or 3 a day from 3 or 4 hens. Check Henderson's chart for breeds that lay well. I would not plan on fewer than 3; one might die, and they do not do well without at least one other around. If you are thinking of meat, you need to do some serious research here in the meat birds section; that is a whole other ball game....
Even if you only want eggs, you will need a coop and run that gives a minimum of 4 sq ft per chicken in the coop, assuming you decide to use the back yard as the run, which then brings up a host of predator considerations. If the run is to be the back yard, you might consider starting with a few more hens than this, because it is likely some will be taken by predators. (Not disapproving of this; I have some truly free range hens, and some younger ones in a yard.)
A coop can be built for next to nothing if you have some materials at hand or can scrounge them. Or you can spend a few hundred and buy the materials and build a coop. Spend some time in the coops section here. Many good ideas for building a coop for nothing or next to nothing. But do have the housing well planned if not already built before you get chickens. Too many get baby chicks, then try to figure out what to do with them. You should be able to house babies in the coop at this time of year with some planning and maybe a little heat from a light bulb, depending where you live. If you get adult birds, this is not a problem anywhere, if you research and plan ahead.
It would help for future questions if you would include your general location in your ID info. Some breeds do better in cold or warm climates, for example. Not suggesting a street address! Just state or country, or northern or southern if California, etc.
Please browse sections like FAQ, coop design, and how to raise baby chicks here. This is an awesome site, probably better than any chicken raising book you can buy. And feel free to ask questions if "search" doesn't do it for you. We are glad to help!