I think it is important to note that the 600cc machines of today are by no means learner bikes, they are fire breathing, 9 sec quartering, rockets, that few people give the proper respect. For your experience to be a good one, it is important that you get the right bike for you. Unfortunately, I would have to know more specifics to make a recommendation but dual sports are a lot of fun and easy to ride, although they are not ideal for freeways.
Other than that, riding safely is a matter of learning to read traffic and driver’s head movements. Buy some good gear, boots, pads, and a good jacket you feel comfortable in are worth their weight in gold and are often priced accordingly. Fashion leather is by no means durable enough to protect you in an accident. As much as I hate to sound like a mother, if you have never ridden before, MSF safety courses are a good place to start and they count for your license test in many states.
Anyway, good luck and have fun. I have not owned a car since I bought my first bike five years ago… there is really no going back.