Keep them in the coop for the first night
The single most useful thing you can do is also the simplest: shut the transported birds inside the new coop for the whole of the first evening and night, and do not let them out into the run until the next day. Chickens learn home by sleeping in it. A bird that spends its first night on the perches, waking up in the coop the next morning, files that coop as its roost; a bird turned loose on arrival spends the evening looking for somewhere familiar and may try to roost in a tree or under a hedge instead.
Put the travel boxes inside the coop before opening them, let the birds step out in their own time, and stay crouched and quiet for the first minutes. Talking softly is fine; looming over them and grabbing at strays undoes the calm you are trying to build.
Water first, then feed, both inside the house
Transport dries chickens out, so the drinker matters more than the feeder in the first hour. Fill it before the birds arrive, set it inside the coop at back height for the smallest bird, and dip the beak of any bird that looks dazed so she learns where it is. Scatter some feed in the bedding as well as filling the feeder — scratching for scattered feed is familiar, calming behaviour, and it tells you quickly which birds are eating and which are sitting hunched and off it.
Do not hang a feeder outside and expect them to find it. On the first evening, everything the flock needs — water, feed, grit if you offer it, and the perches — should be within the four walls they are sleeping in.
Let dusk do the roosting for you
Chickens follow the fading light. If you arrive in the afternoon, let the birds explore the coop through the last hours of daylight, and as dusk falls they will start looking for somewhere high to spend the night. Most will hop onto the perches themselves once the coop is the darkest, cosiest place available. Any bird that settles on the floor or in a nest box can be lifted gently onto a perch after dark, when she is torpid and easily handled; two or three nights of this is usually enough for the habit to stick.
Resist the urge to keep checking with a bright torch and a lot of noise. One quiet visit at nightfall, with a dim light, is plenty: count the heads, match the number against the birds you transported, and look for anyone who has ended up outside the pop-hole.
Lock up like a fox already knows the address
The first night is when a new flock is most at risk, because predators investigate new smells and the birds do not yet know the safe routine. Close and fasten the pop-hole, latch the main door, and check the coop over for gaps at floor level and loose mesh before you leave. A coop that was fox-proof for its last occupants deserves a fresh look — transported birds are stressed, noisy and interesting to everything hunting nearby.
In the morning, open up later than you normally would, let the birds come out into the run in their own time, and watch the first interactions if they are joining resident hens: a few scuffles over the feeder are normal, but a bird being kept off water needs a second drinker placed out of sight of the boss hens.
With KinsLe's Care Teams you can hand the first-evening routine to family or helpers as assigned duties — water topped up, dusk headcount, lock-up checked — each marked complete with a timestamp, so the flock's first night is covered properly even if you are not the one closing the pop-hole.