hello guys, I will have my first interview f2f on next monday. I am excited of course

This will be my first interview.
Job title is : System Administration (Routing)
So as far as i know, i will be assisting to the system admin and also will deal with networking. I am CCNA however i also know that they use Zyxel products (Zyxel ZyWall USG 50). Anyone has an experience with this product ? Any issues and specific suggestions ?
P.S. I had a job experience in a different field. IT is totally new to me...