Selling books

Hello, just created my Amazon seller account. To get familiar with things I wanted to start to try and sell books. Is it worth it to sell books that only net a couple dollars profit according to the Amazon app? I assume you still have to take shipping into consideration. How much will Amazon charge you to store books if they don’t sell? Right off the bat, do you need a FNSKU label maker? How do you gain access to restricted books? I’ve scanned some at home that tell me to ask for permission and it gets approved right away, but it still says restricted. And I’ve heard of creating a UPS business account can be beneficial. Truth to this? Sorry for all the questions. Appreciate it! 🙂