What more is learned about Nick in Chapter 2? Is he similar to or different from the people he spends his time with?

Chapter 2 takes introduces us to Myrtle Wilson and shows us the affair between Myrtle and Tom Buchanan.  Myrtle is shown to be in a much lower social class than Tom.  More than once, Nick as narrator, mentions the tacky tabloid, "Town Tattle", that Myrtle buys.  Nick describes how Myrtle puts on airs once she gets to the apartment Tom has for them in the city - note the dress she puts on and her response to Tom's directive to get more ice: "I told that boy about the ice.  ...These people! You have to keep after them all the time."  He describes the guests that come to the apartment, especially the McKee's and Catherine, Myrtle's sister.  These people are shown to be similar to the people who come to Gatsby's parties - they are self-serving.  Mrs. McKee seems intent upon currying favor with Myrtle by complimenting her several times.  Mr. McKee focuses his attention on Tom, trying to get Tom to open social doors for him and his photography.  Catherine is clearly trying to flirt with Nick, probably hoping she can catch a sugar-daddy like Myrtle did.  Nick observes all of this through a drunken haze.  He tells us early in the chapter that this was only the second time in his life he'd been drunk and that as a consequence, his recollections have a "dim haze" cast over them.   What we learn about Nick in this chapter is, first of all, he is capable of objectivity. He has told us in the first chapter's opening paragraphs that he is one to reserve judgment, but he is actually rather judgmental in his descriptions of the Buchanans, Jordan, and the surroundings.  In the second chapter, he is more objective - describing events and people but letting us make more of the judgments.  In this way, he is different from the people he encounters in this chapter.  Those people have judged Tom as wealthy and capable of giving them something.