This webpage contains ideas for several activities for a toddler or preschool storytime about shapes:

http://cfkidslibrarian.blogspot.com/2012/07/shapes.html

Shapes (Circle) Movement Activity:

A little circle (make circle with finger and thumb)

A bigger circle, (make circle with two hands)

And a great big circle I see. (make a circle with arms)

Now help me count them,

One, two, three!  (repeat gestures for each size)

Credit: http://libraryvillage.blogspot.com/2013/09/toddler-story-time-i-see-shapes.html (This is a great Shapes-themed storytime!)

This page includes storytime suggestions for babies, toddlers/preschoolers, and e-storytime with a Shapes theme: https://jeninthelibrary.com/tag/shapes/