Question about a concert?

I'm going to an ATL concert in May. It's in Baltimore, Maryland. I don't think there's gonna be igned seating, and i've never been to a concert like that before. I was wondering if there's gonna be any moshing or stuff like that, 'cause i wanna avoid it. And if i wanted to get a good standin like up front near the stage, how early should i get to the concert?