On the item's detailed listing page, you need to put quantity of min 1, max 1 (if you only have one unique item), also if you click on track inventory, the windows pops up and insert the number of items you have there. If you are talking about your new store on Auctiva Commerce website you are in the wrong forum. This forum is for eBay/Auctiva. Just in case you don't know.
Hope it helps