The other advice has been great and I agree with what they have said so I will add a new one into the mix. Since you are new you will be starting doing under level games, freshman and JV. If you are officiating the prelim game prior to the varsity do your best to stick around and watch the varsity officials. Check with them to see if they mind you listening in on pre-game, if it's still going on after your game is over. Also if you can sit in on their halftime conversations.

I know a lot of veteran officials have been almost pleading with the younger officials to stick around after their games. I know in my case it has helped me actually get some varsity games because they recognize you and your name and realize that you are willing to put in the time to get better.

Hope this helps and welcome back.