I'm in a nursing program and I would suggest not getting a puppy if there isn't somebody else to devote a lot of time to it. Most people find nursing school very demanding and they end up studying in almost all, if not all, of their free time. Because of this, and the time you will be away from the house, it would not be fair to a puppy and it's training would also take a lot longer.
If you DO have somebody to help, you may still not want to get a puppy yet. Personally, I would find it difficult to go to school and study when a cute puppy was in the house. Not to mention they might make sleeping a bit difficult while they are very young.