This is the piano accompaniment to Gluck's Andante Cantabile. This can be found within the book Old Masters for Young Players. You will hear 5 clicks (1 full measure and 1st 2 beats of measure 2) before the cello part should start. The piano accompaniment starts on the downbeat of the next measure.
Youtube:
https://youtu.be/OzHd2tFZY24