My suggeston is for you to get a Suzuki GS500E (89-2003). You can get them very cheap (usually 500-2000 for older models), they have a steel frame (won't get hurt if you wreck it), power is low (39hp - won't get out of your control), and is air-cooled (very low maintenance). In additon, since they didn't change them all those years, and many were sold, parts are readily available, and cheap, if you do drop it.