Kindergarteners and first/second graders should be working on basic skills like proper use of the mouse, posture and hand position for the keyboard, typing your name and simple words, and locating and opening/closing/minimizing tabs. Learning and story-telling games are great activities for this age.
The games and stories linked here are great for building computer mouse skills,
Teach Your Monster is a
(star code) to 103088 so that their progress will sync to school.