Make sure the know the water source. If the haven’t been drinking yet dip their little beaks in the water, do it with each chick. Peck with your finger at the crumbles (yes, you are now mama hen and show them the ropes). The need a heat source, either a heat lamp or a brooder plate. If you use a heat lamp secure it well!!! Fire hazard is real. Chicks need temp of approximately 95 degrees Fahrenheit for the first week, then 5 degrees less per week. Make sure they can get away from the heat source if they get too warm. Cold and or hungry chicks can chirp a lot but act and sound distressed. If you use a brooder plate (my personal preference) they can go under and out at will and they have darkness at night (even using a red lightbulb for a heat lamp will keep them more awake at night). Check their little bums daily for stuck on poop, if they get ‘plugged up’ they can go bad quickly. Usually pasty butt is only a problem in the first week or two but it’s worth checking them.
Check out the learning center, prepare a coop because the little ones grow fast!
https://www.backyardchickens.com/articles/how-to-raise-chickens.47660/