May I offer some tips/observations? I will start with the positives
1) Can already tell you look the part. Fit, dressed well, and not timid. That alone will help you progress.
2) The strike is absolutely fine. I rewound it and slowed it down and I’d say half the ball was in the channel and half on the chalk. That’s a strike at every level below HS Varsity in my opinion.
3) You need to change your strike three mechanic. This isn’t opinion, it’s fact if you want to move up. Pause the video with 0:02 left. You are looking at the ground, almost 180 degrees away from field of play. What if the batter interfered with catcher? What if runner took off? What if catcher drops the ball so batter can run? Keep your eyes facing the action and POSSIBLE action
4) you have a nice “lock” mechanism (arms locked, keeps your head at the same height every pitch), prob will need to get a little lower as level advances as most college and mlb guys lock with their forearm or grab behind their hamstrings/knees. Only thing there is you drifted with the pitch, try to stay still. When you drift, a pitch that is 1 foot outside (shouldn’t be called) will look 3 inches outside bc you moved closer to it and you will grab it
5) Work the slot, you are directly over the catchers head. Very common for new umpires, but you don’t get a good look at low pitches and especially the low outside corner, will disappear on you. And above all else, is a major safety issue. Batters hardest foul balls tend to be straight back or just to opposite side (watch mlb game where foul balls get scorched backwards). Working the slot reduces number of times you will get drilled. Not so important at the age you are doing in the video but very important when you get to guys throwing harder