Bring whatever you'd like! I actually always brought a box with my tradeable pins, but some brought their traders bags, some wore lanyards, some even brought cork boards! So do what works best for you! Using a box worked best for me because I had most of my traders on the original cards, and I figured I could display everything a bit more easily than with a book. But that's just me!
As for what usually goes on, everyone will normally set up their stuff, and then you can just go around the area looking at everyone else's traders and start putting together trades. It's a nice calm environment, and like I said, everyone is friendly, so it makes for an enjoyable time! I found everyone to be trustworthy too- I had no issues leaving my traders out and walking around the area looking at everyone else's stuff. Nothing ever got stolen! Don't worry about "sharks" either- Casey is great about making sure the event is about having fun, and not about taking advantage of other people. It normally lasts about 2 hours, but some times it went closer to 3 hours because everyone was having such a great time!
To be honest, I don't do trading events very often. But if I had the chance to, I'd legitimately make a special trip from California to come to this one! I've made quite a few friends just by showing up to the event regularly. Great environment, great people- you'll have a lot of fun!