Congratulations on the new chicks, and your upcoming infant!
The box of bedding doesn’t need moved. If they don’t want in it, they are fine. In the beginning, babies sleep on the floor. When they are 8 weeks or so, I will put them up on the roost at night if they have not begun sleeping up there. It takes a few days, and they begin roosting.

If you have any questions on breed and/or gender, please post here. You'll get lots of good help:
I didn’t make my babies sleep inside one summer. Come morning...
I hadn’t had a predator attack before, so I didn’t think they were in danger. I was lulled into a false sense of security.

some people though, just keep their flock confined to the coop and run for about a week so the birds get used to their new surroundings. You may still have to set them on their roosts at night though.