I just made my seniority about two weeks ago. All the advice here is sound. Do not stress the bad days, I had several of them and still do. Had to have a driver come take ten stops from me this week on a new route I was on. It happens. Just do your best, show improvement, ask questions, and ask for feedback. I asked daily how my progress was, and asked for feedback on what I could do to be better. Just keep going. One box, one stop at a time. I worked through my lunches besides a quick five minute snack break, took time while on break to organize the truck (gotta love the quality loads we get!). Area knowledge will improve as you go through your progression. Practice makes perfect!
And as far as the parking the trucks and leaving the building: I had a porter park my truck at the end of the day for me for the first two weeks, literally. I, like you, didn't want to hit anything in that thirty days. One day I even had a supervisor in the morning start yelling at me when I was leaving because I was inching the truck forward and backwards. "Are you going to leave the building today!!!" It's all good. I made it, and I'm sure you will too.
PS-Don't let mgmt bring you down. I got worked up a few times over messages in the diad or rude and threatening comments while going for seniority. Nothing is more disheartening then getting several messages on the board "Are you going to make it?".... "You are an hour over already, pick it up". I told myself it was UPS bootcamp, and they were just trying to see if I could hang. Have thick skin, and do your best. Good luck!!!