There is no one "best" way to learn power chords, as the approach that works for each individual will vary. Some people might prefer to start their power chord learning by learning the chords in 1st or 2nd position, while others might prefer to start their learning process by learning the chords in 3rd or 5th position. It is important to find the way that works best for you, as different people will have different preferences when it comes to power chord learning.