Critical Role is, to quote Matthew Mercer - DM - a show where a group of nerdy-ass voice actors sit around and play Dungeons and Dragons. Vox Machina is the band of heroes from Campaign 1. The show itself starts well into the campaign so we don't get to see the beginnings. The graphic novels are a way of "fixing" that. Truthfully, we have no way of knowing how much of this is from the game and how much was made up for the novelization. Is very entertaining though.
Is amusing how the band of misfits manage to meet, blunder into each other, and eventually become a team.