I would ask the feed store what their policy is on return chicks.
As far as the food question, I have no idea. Really depends of when they start to lay. Chick starter can be fed even after they begin to lay so it's not wasted, you just want to make sure to give them oyster shell for added...
Are you ordering chicks, getting them at the feed store or a person.
You may have options. Depending on the time of year, some hatcheries have a minimum order of 3 on sexed chicks. Usually the feed store had sexed chicks as well. If you are getting them from a person, then it's a gamble. You may...