Safest to start out on the street- a 60cc to 250cc scooter with an automatic transmission. Learn to steer and brake on the street, before adding the clutch and shift lever.
Medium safety- a 250cc Ninja, before 2008 they are uglier and cheaper.
Very little safety- a 600cc 4-cylinder supersport.
You are totally insane- a 1000cc supersport, ZX-14, Hayabusa.
“Banking institutions have banished precious metals and substituted a more fluctuating and unsafe medium; they have withdrawn capital from useful improvements and employments to nourish idleness for the few, who prefer demoralizing pursuits to labors useful to the whole; the peace of the whole is endangered by evils more easily to be deplored than remedied." by Thomas Jefferson,1810 (edited)