Well you can have i think up to 10 devices sharing the same store account....So make sure under settings, store, that they are the same ID and have automatic downloads ON (on all of them). This will ensure that if you add a program on one, the others will download the same program to match. There is no way, without a computer, to set them up NOW all the same. Your going to have to do it individually NOW with the apps etc. From this point on, any downloads will follow suit on the others.
Icloud will sync, mail, contacts, photos, etc with all of them, but im guessing that doesnt matter since its a kindergarten class. Icloud and "store cloud" are different. I dont think you will need Icloud for your class, so if not you can turn that off.