How to read the pictures
The string marked in yellow is the one you play. A circle with a number shows the finger that presses it down: 1 is your index finger. Without a circle, you play the open string.
C2 – B2 12 notes
28 notes for cello, from C2 to Eb4, each with a picture of its fingering. Notes with two names, like A# and Bb, share one picture. Notes are written pitch, as in your sheet music.