Swag,
I wouldn't worry to much about it. Be confident and prepared. It's your first job; it probably won't be the best job and it won't be your last. If you don't get the job take it as a learning experience in preparation for the next interview. Hard work does pay off but so does smart work and use this as on opportunity to reach your next goal whatever that maybe car, fishing crap, college, or helping your family. Best of luck.