Pat,
I broke my left shoulder in 2003. First, let me say that every shoulder break is different, depending on where the break is, how severe a break, etc.
I don't think you should even be thinking about driving at this time. Some things to think about...you may have a strong enough left side to be able to do everything with that hand. Or not. I am guessing you don't have a manual transmission (I did), cause that would be a definite no. Do you have a "touch to start" button, or do you have to use a key? If you have to use a key, how do you plan to reach over the steering column to put the key in and turn? Don't think you'll do it with your bad side, it isn't a good idea do to more than they tell you if you want to heal well.
You do want to do everything they tell you to do, though. When you start PT., your arm will have been flat against your side for weeks while your shoulder was restrained. It is a somewhat slow process to get your movement and strength back. You'll do many different exercises, and do them exactly as they say and at home as many times as they say. Don't "cheat" by not extending properly on the lifts and reaches, cause if you do you may as well not do it at all. By cheating I mean not doing it properly because there is an easier way to do it. The easier way doesn't work the shoulder enough to make progress.
If they tell you to use weights at home, and you don't have any, you don't need to buy them. Use 1 pound bags of beans, or soup cans, depending what you need the weight for.
If you are using pulleys at the PT place, ask them if it would be a good idea for you to get an over the door pulley for home, and ask for a prescription for one. They may have them, or you can get one at a medical supply (or online). The pulley fits over a door, and then you either sit on a chair with your back to the door or do it forward, depending on what the PT says. The pulleys really help because the good arm pulls the bad one.
I had a pretty bad break, and I went to PT for about ten weeks. It was a workman's comp issue, and I was still going after I returned to work. Eventually workmen's comp "rated" my shoulder out at 10% disability. I decided not to do surgery and took the payout and bought a new computer
I was unable to sleep on my back or my left side for at least two years. I can now sleep on my back, but I've never been able to sleep comfortably on my left side since. Also, because of the 10% disability, my left arm does not go all the way over my head. That's my disability, but it is workable. I can do most anything but reach for things on high shelves with my left hand, but I have one of those grabber thingies, so it helps.
As I said in the beginning, though, my experience isn't the same as yours. It sounds like yours is much less severe. I know you, and I know you will be motivated, so you should do well.
{{{ HUGS }}}
Fern
PS--I stayed up to write this, I saw it on my way to bed. You're worth it.