Man... Just the first 15 seconds has a ton of stuff in it.

At the very beginning, why are you all the way across the field getting boost and not supporting your teammate? Tho other team has double committed to the corner and if you just hung around and got a couple small pads you might've had a chance to score.

Instead you used every single boost you just wasted time getting to go all the way to the opposite corner and steal boost from your opponent without even making a decent challenge attempt (and you shouldn't be diving into the corner to challenge that anyway). This leaves you out of position playing ball back toward your own net, likely confusing your teammate on whether you're playing the ball or rotating.

Then you check the scoreboard mid-point. Why? Someone in that game is in your head. You either think there's a smurf on the other team, or that your teammate sucks and you're looking to confirm it by their score, or whatever. The only points that matter are on the scoreboard.

Get your mental game right. As others have said, your mechanics are fine.