New chicks every year or two is a good plan, as mentioned. Ordering chicks by mail works well, unless it doesn't, and always take weather into consideration! Very cold or very hot are both problems, and ordering a tiny number will be very expensive!
Spend time reading up on breeds, arrange the coop and run, get into winter, and decide who you want to add, in spring, or later. and if you want birds that your local feed stores sell, that will also be less expensive. Or, if there's a good hatchery within driving distance, go there.
Mary