Newbie needing help getting started? (Scanlister issue?)

Re your listing problem, if you have the time, I’d suggest listing each book individually, by using the SBN/ISBN where they have one. In your seller account, under “Manage inventory-Add a product” enter the SBN/ISBN as just a string of numbers, eg 123456789, no spaces or hyphens. Look at the existing listing to see how many other copies are already on sale and the prices. If there are, say, 20 copies at 25p upwards, don’t bother - it’s a waste of time, unless yours is signed by the particularly well-known author
This method ensures that you are listing against the genuine catalogue entry. Unfortunately, Amazon’s book section is awash with fake (unnecessary and against the rules) duplicate entries created by (usually USA-based) dropshippers who don’t hold any stock but just list titles at ridiculously high prices (often hundreds if not thousands of pounds) for, say, a very common paperback novel in the hope of conning some gullible buyer to order it. When they do, the dropshipper just buys one of the other, cheaper copies, to be sent to the mug. The more avaricious ones even put in automatic “Item not received” claims to get back the £5 or £10 they paid