For example,
If your left hand was doing the lifting:
The right hand would be grabbing the top right of the bench, the right knee would be on the bottom right corner of the bench, your left leg would be to the straight, to the side, and you would grab the dumbbell and lift it up with your left hand.
What is this exercise called and what does it work?

I am almost 16 and I have a pair of adjustable dumbbells, from 2.5lbs to 40 lbs. I don't want to bulk up too much and just want to build some overall muscle, and no weight loss.
I need dumbbell workout out or weekly routine which I can use to build muscle overall. I can also do bodyweight exercises.
Any information would be beneficial.

Hi, I just found out about the bicep workout called Dumbbell 21's. I had a question for anyone who has tried this workout. How many reps of these should I do per workout?

For example,
If your left hand was doing the lifting:
The right hand would be grabbing the top right of the bench, the right knee would be on the bottom right corner of the bench, your left leg would be to the straight, to the side, and you would grab the dumbbell and lift it up with your left hand.
What is this exercise called and what does it work?

For example,
If your left hand was doing the lifting:
The right hand would be grabbing the top right of the bench, the right knee would be on the bottom right corner of the bench, your left leg would be to the straight, to the side, and you would grab the dumbbell and lift it up with your left hand.
What is this exercise called and what does it work?