This is very tough to me. I can i let the reader know the genders of non-human characters. for example: Jake and Lina are phillisin. Genders are witch and wizard. But in first person, (this has been changed though: One of my chapters said something like: (Don't worry about the grammar. As i said, it has been corrected in the actual novel) He tapped the bell of the lobby’s front desk and a witch named Tory answered. Human genders of course are man and woman, and yes, the human world is in this novel. Its hard to let the reader know about the genders without it being an info dump, or sounding like the character is insulting the other character.