“Faire une passe” means kicking or throwing a ball to a partner when playing soccer or any sport with a ball.

“Faire une passe” means “to make a pass”, with a ball.

Here, considering it’s kids playing, “faire des passes” could be translated as:

To play catch

“Faire une passe” literally translates as “Make a pass”, and as in English, its meaning is very much dependant on the context. It could be :

• To make a pass in a sport: to throw/kick/hit a ball/frisbee/puck to another player.
• To pass [by] someone or something while driving or running.
• To make a pass at someone: to say or do something that is intended as romantic courtship.

In the case of Le Petit Nicolas, it’s probably sport-oriented, but humor is probably intended with ‘jouer entre les bancs’, ie ‘to play between the seats’ as referring to something akin to intimate play.