My first bike was a Honda GL1000 - I'd never ridden a bike before either, and was talked into trying the GL1000 by my girlfriend's stepfather. Once I tried it I realized it was not as difficult to handle and manoeuver as I had anticipated. Don't be intimidated by a moderately sized motorcycle.
Certainly statistically more scooter and motorcycle accidents happen off the highways as opposed to on them. My own experiences bear this out. I've covered countless thousands of miles on about a half dozen big bikes - commuting to work, short trips, long trips and touring. Three collisions in about ten years; all at less than 50 mph on minor or city roads.
First was an off-duty german cop who made a U-turn in front of me at night on a city street, second was an "escaped" sheep in farm country, third was a man with family on a minor road near an intersection who tried to swing a quick U-turn, didn't clear the curb and abruptly "appeared" in front of me "parked" as it were across the lane. It is possible, perhaps arguable, I could have avoided all three had I been excercizing more caution. Riding a scooter in all three instances would not have helped me.
One general cause of motorcycle (and scooter) collisions are; vehicle operator "fails to see" motorcyclist. This can be when the vehicle was turning, overtaking, changing lanes etc or when entering an intersection from a "yield" sign or other right of way control, crossing a major road from a minor road, etc etc. Your best ally therefore is your senses; observation and caution. The safety class is a very good idea.
I would take the class, and try out a few motorcycles and scooters and see which you feel more comfortable with.
