We have gotten our wristbands a couple different ways...
We have not attended the concert (just not interested in the group playing). One year we arrived at the event location (along with everyone else) just prior to the 6:00 pm opening. In short, we had to stand in line to get our wristbands, stand in line to wait for the doors to be opened, stand in line to get our plate and glasses, and fight the rush of people as everyone rushes to get their favorite spot (not the most relaxing way to start the event).
Last year we were running late (15-20 minutes). As a result there was no line to get wristbands, glasses, etc. We don't usually spend alot of time sitting down, so finding a table to camp at is never our priority. Even arriving late, we still ate/drank our fill before the event concluded.
As long as you have a reservation (and paid!!), the most enjoyable approach, IMHO, is to wait for the wave of people to subside and casually stroll in after the event starts.
Above all - ENJOY!