You need to play an F chord using the Hendrix-style shape with your thumb playing the root note. Once in this position, you will have your little finger free to play the 3rd fret of the high E string.

This first chord is a nice, easy fingering for C/G. Do your best not to accidentally mute the open third string. The F chord is the fourth chord in the key of C, so this will go well in a ...