What is the most important quotations in chapter 2?

Important quotations really depend on how you interpret the novel. You might consider this one

My sister, Mrs. Joe Gargery, was more than twenty years older than I, and had established a great reputation with herself and the neighbours because she had brought me up "by hand."

The term "by hand" has two meanings to it. It speaks to Mrs. Joe bringing Pip up as well as the regular beatings Pip endured under her.