You'll need at least 2 because chicks are social beings and they're fairly easy to care for.  
Consider buying a "Bird Workshop": A 3 hour, on-site, hands on training on how to own and care for chicks, hens, and eggs.
After a few weeks of growing strong, most breeds will lay their first egg around 18 weeks of age.
Once your female chick grows into a backyard hen, she will lay up to 250 unfertilized eggs in her first year. A rooster is needed to produce fertilized eggs.
Breed: multiple
Color: Multiple
Age:  1 day old & up
Sex: Both
Price: $5.00 each