Back Blast

You scream, explode, and launch yourself 20ft in a direction of your choice, this movement does not provoke opportunity attacks, and the spell emits a thunderous boom audible out to 300 feet.

Targets within a 10ft cone opposite the direction of your launch, and the first creature or object you crash into must make a constitution saving throw or take 2d6 thunder damage, or half as much on a success, you automatically succeed the save.
The first creature you crash into that fails the save is pushed half of the remaining distance and are knocked prone if they are no more than one size larger than you.

At Higher Levels. When you cast this spell with a slot of 2nd level or higher, the damage increases by 1d6, and the distance you are launched is increased by 10ft for each slot above 1st.