Two orphans where one gets picked to go off a life with the rich. It’s a futuristic post apocalyptic world. Main protagonist is black. There are AI robot cops

When Alita awakens with no memory of who she is in a future world she does not recognize, she is taken in by Ido, a compassionate doctor who realizes that somewhere in this abandoned cyborg shell is the heart and soul of a young woman with an extraordinary past.

In his travels as a bounty hunter, Hunter–Warrior and cyborg healer Ido one day discovers and repairs the remnants of a cyborg whom he names Gally. Though possessing the body of a young woman, Gally now embodies Ido's most sophisticated and lethal cybernetic skills. The preternaturally strong, amnesiac Gally begins to forge a life for herself in a world where every day is a struggle for survival.