Just acknowledge you missed the call. A simple raise of the hand, or a nod of the head can calm the parents and the coaches (unless it was a game-altering call, then oh boy, haha). Maybe give a make-up call on the next strike? BUT THIS CAN BACKFIRE ALSO you called a ball a strike and strike a ball, and some may not pick up on the "make-up call", and just make parents and coaches even angrier.
Never do any of the above.
99% of the time you will be just throwing fuel on a fire.
It is not the umpires job to try and calm parents down or placate someone who is upset - and honestly I don't care (or notice for the most part) if spectators are upset or not. Most close calls are going to upset one group or another and I am not going to be influenced or seen to be influenced by who has the loudest group. And I have umpired a couple of sports at the D1 and International level in front of crowds up to 20,000+ where basically 19,000 people were for one team and started in on you the moment you walked out so crowds are just background music to me
If you want to recover from a bad call, the best way is to re-focus and make as many good calls as you can from that point on.
Never, ever do a make up calls and you have now made TWO bad calls. Great way to show that you don't know what you are really doing.
We don't have many younger umpires coming through. Simple as that. We used to train them in rec and then move them up - and during rec season you could get travel players umpiring. But now it is year round travel, so they are not available. We have several Vietnam Vets in our umpire room. - and a lot didn't come after COVID.All I know, in my area we have had to cancel several high school games because we can't get enough umpires. Part of it is how they are treated by parents, coaches, and sometimes players. The umps are just tired of being treated like crap.
The original poster was already doing HS games his first week umpiring. That is NUTS no matter how much they know about the game.