Before paying anyone to edit your book, you can have beta readers read it to give you advice for free! (Yes, sometimes beta readers are paid. Those ones will probably guarantee better feedback than randoms from Facebook, but it’s up to you.)

Beta readers provide you with advice for the content of your book—yes, it’s that general. If you want them to focus on something specifically, ask them to do that: “Hi, when you’re reading my book, can you look at how the chapters are broken up? Let me know if you think it’s effective or know of another way to do it.” Otherwise, they’ll tell you whatever they think about your book from a reader’s standpoint.