The first season trailer can be found here

"The story takes place in the world of Remnant, which is filled with supernatural forces and shadowy creatures known as the Grimm. Prior to the events of the series, mankind waged a battle of survival against the Grimm before discovering the power of a mysterious element called Dust, which allowed them to fight back against the monsters. In the present day, Dust is used to power magical abilities and weapons. Those who use these abilities to battle the Grimm are known as Huntsmen and Huntresses. The series focuses on four girls, each with her own unique weapon and powers. Together, they form a team at Beacon Academy in the city of Vale, where they are trained to become Huntresses."

The series can be found on the RoosterTeeth website, or on Youtube