Don't bounce the weight off the ground. Lower it and re-set.
Your first rep looks pretty good. Obviously I can't tell how tight you're getting just by a video, but remember to do that. After that, you lower the weight in an uncontrolled manner and bounce it off the ground. I bet you're losing a ton of tension. You're also locking out your knees really early on every rep thereafter. Also, you're only really lifting it once.
Not that there's no place for getting some bounce, now is not the time. You are a beginner. Strength is an objective thing. If you add weight to the bar, how can you be sure you're not just bouncing harder to compensate rather than getting stronger?
That's my main critique. Additionally, I would advise against using a mixed grip this early in your training career. It will do bad things to your shoulders down the line if you're always using it.