Final answer:
Sofia Coppola joined FFC at Zoetrope Studios as a young filmmaker.
Step-by-step explanation:
The young filmmaker who joined FFC at Zoetrope Studios was Sofia Coppola. Sofia Coppola is an American filmmaker, screenwriter, and producer who started her career at a young age. She joined her father Francis Ford Coppola's production company, Zoetrope Studios, where she worked on various projects and eventually made her directorial debut with the film 'The Vir-gin Sui-cides' in 1999.