You should have received, in this envelope, one or more bluesheets, describing the group or groups that you are involved with. You are essentially playing yourself, unless you also got a character sheet stating otherwise, or your bluesheet indicates otherwise. Write your "character" however you see fit, and have fun with it; don't feel constrained by "real" reality too much. If you got multiple bluesheets, you are involved with multiple groups, which may contradict each other a bit; rectify their relationship as you like -- play an associate of both groups, a double-agent, or whatever makes sense to you. It's possible to rectify any two groups, if you use a little imagination. If you got a character sheet, that says who you really are, beneath the convenient cover identity you're using, and/or may give you more details about how you interact with your particular group(s).
Although the principal action of the game will be occurring at Any Port in a Storm -- The Con-Chair's Wake, you should feel free to roleplay, plot, organize, and conspire over the rest of the weekend (within the constraints of the rules). This game is what the players make of it; enjoy.
Who Killed the Con-Chair? was conceived and designed by the late, lamented Jeff Diewald, and written by Mark ("Justin") Waks, who is also acting as GM. Note, however, that this is a very mechanics-light, roleplaying-oriented game, and isn't intended to require much GM intervention. (Read: there is one GM for over 200 players. If you can do it without a GM, do it.) Or, in other words: you're on your own. Welcome to Real Life.