This symbol is a quarter rest. It indicates one beat of silence. Do not play any note. Remember that small counting numbers are placed under rests.
The next chord you will learn to play is the F chord. To play the F chord, use the first, second and fifth fingers of your left hand, as shown in the F chord diagram. The F chord introduces the note A below middle C.
When changing between the C and F chords keep your fifth finger in position as this note is common to both chords. When changing between the F and G7 chords keep your second finger in position as this note is common to both chords. Practice changing between C, F and G7.
This is a half rest. It indicates 2 beats of silence.