I don't know for sure what will happen this year, but based on the previous 3 or 4 years, there is usually no side events the day of the grinder.
On Saturday, Free events include 8 person single elimination pick up tournaments, and league play. In the 8 person tourny, at least one win generally gets you a prize. You also can play League - play any person and then the winner draws two cards from the stack and gets to keep the one they want. The cards are either a foil, a rare or direct you to winning some other item - playmatt, theme deck, hat, etc.
I think they also have had 8 person sealed tournaments, and team (2vs2) tournaments although these will cost money.
On Sunday they start with Undaunted Prereleases - Three or 4 flights worth. The cost is about $25 US. Once these get going, the side events will switch back to league and 8 person pick up tournaments. Side events close down around 3 or 4 PM to get ready for the finals in both the VCG and TCG championships.
There typically is a gaming room that is open 24 hours a day starting either Thursday night or Friday morning, where you can hang out, trade and play pick-up games with people from around the world.