what's a Luna?

My name is Ali (Alice) I am Nineteen years old and from the age of eleven up until i turned eighteen i lived in a boarding school. I am an ophan. Been one since the age of 10 when i lost both parents to a drunk driver. I have no family left and only a hand full of friends but im happy.
I never expected everything to change on my 20th birthday. I never thought I'd be kidnapped by werewolves because I was the supposed Luna of The True Moon pack and mates with their Alpha Michael. I didn't even know werewolves existed