If left on their own, chicks will prefer to huddle together for a while after moving into the brooder. They will see the older chickens, if you have them, and they will learn from them. Chicks have an instinct to roost on any high horizontal space, such as braces between studs, until they no longer fit, then they'll consent to roost on the perches.
I teach my youngsters to roost a few days after they move into the coop. (Five weeks) I place them on the perch and keep putting them back up when they hop down. It helps to squeeze them all together so they're all touching, giving them the benefit of huddling, but they're all in a row, instead. I place the most timid one against the wall, and the bravest one gets the last spot on the perch on the opposite end from the wall.
In the span of just a couple or three nights, they're roosting on their own.