First you earn the Army's Black beret. Then, by going to the Elite Schools for Special Forces and Airborne and completing the courses, you earn the right to wear.
The United States Army Formed & Inspection Ready Black Beret with Flash is Sizing: Adult; Leather band; Flash pre-attached; Pre-formed; Shaved; No eyelets .
This is typically why a beret must be shaped, as it will most likely resist holding this shape when brand new. Pre-formed, cut the cardboard, and then put the stupid looking thing on your head.
Tbh I spent forever shaping mine at BCT and it still holds up 6 years later.
The United States Army requires the edge to sit one inch above the eyebrows. However, if your beret is already visible pilled before being shaped, shave it.