Are there metal detectors going in? If so do I need to bring proof of metal in my back? Also do they have handicap places in front of the stage?

There are metal detectors. They did not pick up my extensive hardware holding my ankle together. There is an additional screening that takes place if a detection is made. I did see someone try and bring in a bottle of Tito's and we had to drink it at the entrance. They did not lose their place in line.

There are metal detectors when you enter. I'm not sure if you have to show proof that you have metal in your body. There is usually a wheelchair accessible area next to the AV booth. But it depends on the concert.