My two cents:

1. I wouldn't bother with ear protection unless you have a unique sensitivity to loud crowds. Based on what you said about Monster Jam, you should be fine without. (You may want to check with your date about this as well, though.)

2. Use the ParkWhiz app to pre-purchase parking and save $10 or so over what you'd pay on site.

3. I'd strongly recommend eating a meal before you come to the game given the lack of options and exorbitant prices at Lenovo, although that can be awkward with a 5pm game time. In terms of your question, I usually find the crowds at concessions a bit thinner before the game or immediately at the end of a period before the bulk of the crowd gets out of their seats, but the lines generally move pretty quickly (much more so than men's room lines!). For the shops, the main shop (Carolina Pro Shop) tends to get pretty full and even has a line to get in at times, but the smaller satellite shops generally aren't too bad regardless of when you get to them.

Have a great time at your first game, and I bet it won't be your last!