Answer:
Nick has a good house, saying that he is Gatsby's neighbor, but nick isn't cocky about how big his home is. Nick is a wholesome person that is happy with what he has
Gatsby has this gigantic house that is filled with all kinds of things that are all expensive and valuable. Gatsby is also new money, meaning he makes his own money instead of inheriting it.
Tom and Daisy have a big house with lots of stuff, but not as big as Gatsby because Gatsby makes a lot of money. Tom and Daisy are old money so they inherit all of it.