ok please dont flame me.

im close to 300 lbs (wow) and i really wanna get a bike, i know nothing about them but im willing to learn and take the class to get my lisence legit before i even purchase one. but before that, i just wanted to know what would be a good starter bike for a big guy? i was thinkin 600cc or 750cc? does that sound. i dont need anything to be stuntin or anything, just something to drive around when i dont want to drive my car