Do you really need to start with a beginner racquet when learning to play tennis?

No you don't need to start with a beginner racket. I started with a Babolat when I was 9. Let me be claer that this was not like the aero pro drive or pure drive or any pro model. It was an intermediate racket (Babolat XS). Now I play with the pure drive. I would recommend an intermediate racket. Go to Babolat.com and there is a section that has all intermediate rackets so check those out.