Then buy good quality protective gear (jacket, gloves, pants, boots), the best helmet you can afford (Arai is the BE$T, but they are expen$ive) and then consider buying a used, 250-350cc Dual purpose bike. Say $2 grand max for the bike.
ADVANTAGES:
You can ride it off the paved streets: it is considerable softer to fall over on dirt than pavement.
You can still ride on paved streets/highway LEGALLY.
They are tougher and much less expensive to repair & maintain than street bikes.
You can take the time to learn to ride safely.
You can always buy a more powerful motorcycle later...
Any modern 600cc sport bike is too much motorcycle to learn on, unless one is an accomplished BMX rider, go-kart racer, etc. WAY, way, WAAAAAYYYYY too much of an opportunity to kill yourself (or worse!)
