Another type of chord you can play is called a seventh chord. A seventh chord is indicated by the number 7 written after the chord name, for example G7.
The G7 chord contains a new note B which is next to the C below Middle C. Play the B with the fifth finger of your left hand, and use your first and second fingers to play the G and F notes, as shown in the G7 chord diagram.
In this song, the right hand plays the melody while the left hand plays the chords C and G7.
Practice each hand separately until you are comfortable with each part, then sing the melody while you play the chords. Then play both hands together and count as you play.