at least 4 sq ft per bird in the coop. and 10 sq ft in run if are going to have a run.
4x12= 48 sq ft at least coop 6x8ft and 10x12= 120 sq ft the run 10x20 ft
have water inside n outside have good ventilation in the coop be able to walk into your coop.
have windows on all 4 sides so u could open the windows for good air flow.
u need at least 4 nest boxes [3 hens take turns in one box] decide if u want the nest boxes inside of the coop or have them stick out from the coop. if you used chicken wire remember it only keep them in does not keep predators out so dont use it in the begin
other will give u more ideas