FBM book seller

Hi all! I just created an amazon seller account. I chose a FBM account because I have about 60 books I want to sell.

Questions: 1) when it says buy Amazon shipping, that is just the label and cost of shipping, right? So I need to purchase packaging on my own? If so, recommendations for shipping packaging stuff? 2) I was confused by Amazon shipping so decided to just go to the post office but it was expensive. So, do you all just buy Amazon shipping or go your own way/route? 3) should I increase shipping cost from 3.99 to something else? Or increase product costs across the board? I’m only selling new/used books.

Thanks for any and all help!