I had my nose re-broken when I was 16. You will have black eyes and there was a lot of facial swelling and I didn't look so great for a couple of weeks.
You also have to be careful not to sneeze, they teach you to do it through your mouth or you can re-break your nose.
I am really glad I had it done in the end though, I can breathe a lot better, but it was a longer and more painful recovery than I had expected. I am not sure if it was because I was young, my expectations were a bit unrealistic. I didn't like to take pain meds, but I found that I had to for the first week or so.
The other thing that surprised me is when they took all the packing out of my nose, the size of the stuff that they had put in there! lol
I was a teenager, so I was embarrassed and stayed at home most of the summer as I didn't want to be seen like that. I can't remember exactly how long it took to heal completely, but I know at the end of the summer, I was fine.