In Lesson 13 of Book 2 you learned the C and F hand positions. In this lesson you will learn the G position, which you should use when you play songs which contain the G and D7 chords.
The left hand G position covers the notes from F# up to D.
The right hand G position covers the notes from G up to D.
For this song both hands are in the G position. In the first four bars, the right hand plays the melody and in the next four bars, the left hand plays the melody. Practice each hand separately before playing both hands together.