I have ridden a motorbike for a few years on road and many more years offroad before that. If you drive a car and can stay on the bike you will be fine, it is very easy.
It is much more about road use then bike handling, and you have the majority of this you know from driving. What they don't tell you and you should be aware of are dangers like wet white lines, man whole covers etc.
Bring a helmet, good gloves, good jacket and decent shoes. Motorbike boots or walking type shoes. Maybe a flask of tea, you get pretty chilly on your first time out.