Yes, the boards are like the parks where they have to trade with you.
As you near the front of the line, pick two pins you want to give up. Many people choose pins from booster packs or things like that.
When it's your turn, you give the CM the two pins, then you step in front of the board. I forget the amount of time. It's 30 or 60 seconds to find two pins you want to trade for.
Believe me, I was more than a bit afraid last year, but it was a blast. We had enough fun that we tried to sign up for the Saturday dessert, but it was already sold out.
There are many levels of traders there. Some are very, very serious. Many are newbies or most casual collectors and just having a good time.
Personally, I'm not much into the pin tables, but I really enjoy the boards. It's an opportunity to find some really nice pins.
The first hour or so, I was in a bit of shock. The boards have a ton of pins. A couple times, I ran out of time and just picked a couple pins. The CMs could tell I was a rookie last year. As the day went on, many people in line gave advice. By Friday afternoon, I had no problem with the boards. On Saturday, I received even more advice. By the end, I was finding a few Artist Proof and Pre-production pins.
If you can afford it and enjoy pins, it sounds like this is a great year to go. From what people are posting, the last Villains event (years ago) was extremely popular. Many people seem to be coming back to pins just because of this years theme.
If you decide to go, send me a PM. I can give you a bit more advice. (I'm far from an expert.)
BTW, forgot to mention, I started last year by having my pins in my pocket for fear of what others would think of what I was trading. I realized there were plenty of us doing this.