Welcome to BYC

from San Diego High Desert.
Its Very good that you are planning before getting Pop door implies that they follow the rules....

Best thing is to Condition them to come in when its meal time... A call or whistle and feed. White millet is like crak to them but so is Scratch and or Wild bird seed. I used "Treet... Treet... Treet" and they would come flying out of the boulders Fussing at me "its about time"....
And of course the chickens were Johnny on the spot... "Hurry before the Guineas get here" Id lock em all up at about four or five.
How Many Guineas are you getting.
8 by 8 by how tall?
For what its worth at best 64 Square feet is good for about 6 chickens ... as a run Guineas need more space...
Recommended flock size minimum is at least five... More is better. Ten Guineas is great But when you buy from a Hatchery the minimums for Keets are usually around 25.
When I first got into guineas I adopted five adults. My coop size was sixteen by twelve by six feet tall. Dog Kennel panels. The roof was kind of a top hat arrangement lifting the center up another three or four feet. The top was then covered with Heavy duty Tarp...
Our climate is very much like the natural climate where Guineas Originate. So I didn't build a "Coop" space for them. We do get snow so the tarps got expanded to cover prevailing winds and Blowing snow.
circumstance has me with out poultry for now. But when I rebuild I Hope to raise Guineas for sale locally and for my table... Jumbos are on my want list.
Hope R2elk chimes in hes a wealth of information. I have learned a boat load from him.
Take a look at Guineas 101 as well.
deb