Finding the key:
This key signature has three flats. The flat before the last one is Eb. That is the key; E Flat.
Study and play the E Flat Major scale . Say the pattern of steps as you play.
Right hand fingering: 2, (thumb under) 1,2,3,4, (thumb under) 1,2,3.
Left hand fingering: 3,2,1 (fourth finger over) 4,3,2,1 (third finger over) 3.