Great to have new officials. I did my first BB game 30 years ago. Some rules, mechanics, whistles and even shirts have changed, but most things have not changed.
Browse the rule book as often as possible. Even now, I browse it several times a week. "Know your definitions and be familiar with the rest of the book."
Be firm in your calls. "Sell" your calls with good mechanics and confidence. Take your time, don't rush it out there.
Be ready to listen to coaches. They like to vent. Try some humor with them. I have improved immensely over the years in this area. Admit you blew it if you did. They love to hear that.
Talk to other officials. Observe.
Don't rush to move up in the ranks. When I did my first varsity game, I realized that I wasn't ready. And now, even though I have done Junior High to Junior College, I still do Junior High games. I love it at that level still.
Have fun with it. You are doing your best. You are there for the kids. Ignore the idiots in the stands. There are more "expert" officials in the stands than "expert" coaches, if you can believe that.
Don't be the 'boss' out there. You are there to keep the game safe and within the rules. You are not the entertainment for fans, the kids are.
And, after 30 years, I still haven't had that "perfect" game.
Thanks for being an official!