The Power Chord Shape
First let's check out how to get our fingers in position for the two-note power chord. First place your index finger in the 3rd fret of the low E-string. The only other note we'll need is in the 5th fret of the A-string. It would be most correct to play this with your ring finger. But since we're just starting out with these, you're welcome to use your pinky instead if that's easier. It is for me.
This is a two-note power chord. It's called a power chord because it doesn't have a strong mood like our happy major chords and sad minor chords. This one is very neutral sounding and works really well with aggressive rock guitar tones.
You probably notice that we're not using any open strings, which means we can move this around all over the neck. Just make sure you keep a fret in between the two notes. Once you move it around you may get the sound of the open strings above the fretted notes. To fix that, we'll have to break the rule about fretting with the very tip of your index finger. Instead we'll try to fret with part of the index finger instead of the fingertip. When you get this right, you'll feel how your index finger naturally rests on and mutes the higher strings. It doesn't have to mute all the strings necessarily; just the ones that are closest to the fretted notes.