The low notes on the piano are played with the left hand. They are written on the bass staff.
The first note you will learn on the bass staff is the note C.
Play the C note with the fifth finger of your left hand.
When we write a note on the middle line of a staff, the stem can point upwards or downwards.
Play the D note with the fourth finger of your left hand.
When we write a note above the middle line of a staff, we draw the stem going downwards.
Play the E note with the third finger of your left hand.