Other than being male and female? There are no differences. Yes, demons can feed from whomever. But the University has the feeders in place just to make sure there are people available to feed them.
As for who knows about the species, all founding families and feeders know about the curse. Both groups know for certain that if someone has a founding family last name, they are one of the species. However, this doesn’t mean they know about everyone else in the school. They are skeptical and easily figure out who everyone is, but they don’t know right away.
Non-feeder humans have no clue, unless someone has told them.
Everyone else it is up to the RPer. This would be part of their backstory whether they know about the curse of the school or not and how much they know. But you can basically guess that most people don’t know what everyone is, because it’s supposed to be kept a secret.