You launch a bolt of compressed air towards a creature within range. Make a ranged spell attack against the target. On a hit, the target takes 1d8 bludgeoning damage.

A target hit by a bolt must make a Strength saving throw or be pushed back 5 feet. 

The spell creates more than one bolt when you reach higher levels: two boltss at 5th level, three bolts at 11th level, and four bolts at 17th level. You can direct the bolts at the same target or at different ones. Make a separate attack roll for each bolt.