There will be cosplay. There may be extra free goodies up for grabs (in certain stores). There will be riots and havoc in the street. It will be a generally good time for the whole family. Especially if the sun comes out. Go early though. Stocks are limited and your big outlets will probably already be tapped if you leave it till late in the day. If you don't see any FCBD bannered comics on the shelves, ask the staff. They'll know what you're talking about.
Ergo please do not ask your comic reading friends to pick up a free comic for you. Typically, shops do not hand out more than one copy of each comic to one customer. Often they will also put a cap on how many free comics each individual customer can take. So no, (name censored) I can't pick up a free comic FOR you. Get it yo own lazy self.
But seriously though, going in person is just a better idea anyway, because if you stay at home you're gonna miss out on a bunch of awesome cosplay. Maybe even a reason to dust off something of your own to wear, hmmm?
Now, if you'll excuse me, I have a Spider-Man costume to iron.