I have a few shop sections already but when I am in duplicate mode for a new listing the shop section just says "add a new section" I cannot put the item in a section that already exists. Wee bit of a glitch.
Yes, just leave it and when you're done and made it active, go to the listing manager, listings and use the quick edit button at the top right to add it to the section it belongs in. This has been a glitch for a while now!