I don't know how to select quotes from the book to use in an essay/exam

Rather than aimlessly searching through a novel looking for a quote, it is far easier to have a bank of quotes that you know well and can analyse, which can be applied to a variety of questions. To make sure the quotes selected are applicable to a wide variety of questions, you need to decide the 'topics' of questions that are likely to come up e.g. family, death, grief, and make sure you have a decent amount of quotes for each topic. If they overlap topics, that's even better! This is the smartest way to revise for English. The misconception that you need to know the whole novel inside out seems very daunting, but all you need is a few quotes you are comfortable with.