Gym Class technique
The first one is the technique that taught you in the gym class. I see using this method from a lot of people but I absolutely don't recommend it.
It will slow you and it will drain out all the energy from your arms!
Basically, you go up the rope with only the arms strength, using your legs only to maintain the rope stuck in position.You can manage to get up a rope using this method, but you’re working twice as hard.
The legs muscles are stronger, use them!