This F note is written above the top line of the staff.
As you can see from the diagram, the high G note uses the same fingering as C and high E. You now know five different notes which can be played with this fingering - C, G, C, high E and high G. The following song uses the top four of these notes. Before you play the High G in bar 3, imagine the sound of it in your mind. This is a useful technique commonly used by singers for reaching high notes accruately and consistently.
This is the two four time signature. It tells you there are two beats in each bar. In % time the note and rest values must add up to the equivalent of two quarter notes per bar.
Here is a piece by Johann Sebastian Bach which is written in % time and features high G.