When does the convention actually start on Saturday? I heard 10 AM but I'm not sure.

it's running 24 hours, so I guess technically it starts at 12:00.00 AM :) Although unsure how it is if you need to register at the con since I haven't seen any mention of at-con registration times.

The tentative schedule is located here:
schedule . vrillusions is right. This is a 24-hour con and something is always happening at any given hour. Friday is the first actual day of the con.