I am only new to this club and have only recently bought the book, I would like to know if I should read the book first または see the movie?

I think あなた should read the book first, it's way better than the movie (for me) and there's a lot of scenes that doesn't 表示する at the movie, but be patient because the first chapters are a little bit slow,

Read the book. Don't 質問 it. Just read. :)