This symbol is a quarter rest. It means one beat of silence. Do not play any note. Remember that small counting numbers are placed under rests.
There is a quarter rest on the first beat of the first bar. The two dots at the end of the second bar mean to go back to the start and repeat the piece.
To play the F chord, touch the lowest F key. Play the F chord with the fifth finger of your left hand.
This is a half rest. It indicates 2 beats of silence.
Sometimes you will see the letters N.C. written above music. This stands for no chord, which means you cannot play any chord until a chord symbol appears.