Hey man, so everybody else has answered your questions pretty well, I just wanted to chime in and say that it might take you a bit longer than you anticipate to get comfortable driving a package car.
I didn't start to get comfortable until a few weeks after I qualified. While I was qualifying, though? Felt like I was out of control at all times even though I had it well in-hand. Every day felt a little bit better than the next, and eventually I found my groove... then I qualified, and that gave me a huge burst of confidence. Wanna know what I did with that confidence on my 31st day of driving?
They took me off my training route and I took out a mailbox, lol.
I say all that to say this: We're considered rookies for 2 years for a reason. Management doesn't expect you to be comfortable, they just expect you to be safe and follow the methods. If you just remember to stop, call and wait whenever you're in doubt or feel sketched out about something, you'll be fine. Just try to make that phone call before you make any decisions that might result in an accident, no matter how minor (remember, UPS considers pretty much everything to be an accident, whether you crack a branch off of a tree, tap a garbage can with your bumper, leave any kind of rut in somebody's yard or go all-out and t-bone an ambulance in an intersection.)
Keep your wheels on pavement (dirt roads are the worst, though) and always remember that it's okay to stop, call a supervisor and wait for proper instruction to be given.
That actually seems to fit about what I've felt and am feeling.
Collected all the method sheets I could, studied a little, but that just made the feeling worse. Your message and a few others plus talking with some of the drivers at the hub, not about the driving but the confusion and nervousness and they all said the same thing about not feeling in control even though they were and to just take it one stop at a time.
Thanks for all the advice guys.