Honda Rebel is popular for beginners
I think most riding schools use the 250cc cruiser style bikes because they're small, light, easy to manoeuvre and cheap. If you get a 250, you'll probably want something bigger in a few years, so don't spend too much on it.
Ducati's are a sexy Italian super-go-fast bike. A 250 cruiser is a slow beginner bike. I'd spend $1500 or $2000 on a slow bike to learn on. In a few years, when you're confident in your riding, buy your Ducati.
A car, with air bags, seat belts, four wheels for better stability, and a metal body to offer some kind of protection in an accident. Do you know what they call motor cyclists in Hospitals? Donors.
A Tricycle :)