Sometimes when you play a chord, instead of playing all three notes together, you play the lowest note of the chord shape (chord fingering), followed by the other two notes of the chord. This is called a broken chord.
In this song, which is written in * time, the C chord is played as a broken chord. The lowest note of this C chord shape is C.
In this song, which is written in ^ time, the F chord is played as a broken chord. The lowest note of this F chord shape is C.
In Lesson 1, you learned to play the G7 chord using the B, F and G notes. Here is a different way of playing G7 which uses the D, F and G notes. To play this new G7 chord shape, use the first, second and fourth fingers of your left hand.