I need to know if Adobe sells the InDesign program on a disk? I teach in a prison and cannot be connected to the internet in any way at all!
You don't need a constant internet connection to run CC apps—there just has to be a monthly connection to confirm the subscription. So you could on a laptop if that helps.
The actual Adobe CC products will every now and then require a connection to the internet (Adobe's validation server).
Teaching doesn't necessarily mean to teach a special programm. You can teach the principles of layout programs just as good with another program like the freeware Scribus or the inexpensive "Page Plus X9" by Serif.com. You can download PagePlus and/or get a disc.