The debut of the 2nd episode, as noticed by many of the readers of the novel, saw much of the plot scrapped in favour of pushing the anime forward. This meant that explanations of the different player groups and how they’ve been adapting to the SAO system (be it through forming guilds, or becoming thieves etc.) are all but lost.
If you do wanna read up though, baka-tsuki has an excellent translation of it here. That link takes you to where the current episode is, so avoid reading ahead too much if you don’t want spoilers. The episode itself is action-packed and immensely entertaining, with liberal use of CG and visible effort in battle choreography.
Definitely one series you won’t want to miss this season. 🙂