I own an yfz-R1 1000cc, ridding sence I was little... (dirt bikes... quads)
a good one to start would be a 600...

I'm about your size(a little taller),..I've owned around 12 road-bikes in the past 20 years or so(everything from 400'* to 500'* to 650'* to750'* to 1100'*),...took a Military safety course after I had bikes for about 3 years.You can handle about any bike that you want,just take a safety course,you'll learn a lot about riding safely and how to handle a bike,..and don't worry about dumping the one you get,...has never happened to me( or any rider with a little common sense).I would go for a mid-size bike in the 600-800cc range,...anything smaller and you will probably be sorry,after riding it a few months.I've got a Suzuki 800 V-twin Marauder cruiser-bike now......Great mid-size bike(50 HP,same as a Harley 883).Older(5-6 years) 750 Honda'*/Suzuki'*/Kawasaki'* are good all-around 'learner' bikes and can be bought for little $$$$,just about anywhere.

I don't want to. If I do the dash in my car and 18-wheeler, I know I will do it on a bike. Too much inner peer pressure.