Learning left from right is confusing and can be a challenging concept which requires repetition and patience for the child to understand it. 
To begin with, I teach this concept by primarily identifying their dominant side and introduce this term first. 
Gradually with the help of activities and engaging games such as drawing, dancing, muscle memory games etc I re-enforce the left and right. 
With activities such as scavenger hunt, treasure hunt they also are exposed to the sense of...