Practice an A minor chord. Position your thumb on the A on the fifth open string. Place finger one on the third string on the second fret. Place finger two on the third string on the first fret. Position finger three on the first open string.
Push the thumb down to pluck the string, then follow with the first, second and third fingers to create a plucking motion on all strings.
Alternate between C major and A minor. To play C major, hold the thumb on the third fret of the fifth string, the first finger on the second fret of the fourth string, the second finger on the third open string and the third finger on the first open string.
Repeat this pattern several times with a metronome until you can play quickly and effortlessly. Once you get this basic pattern down, include additional chords.