i suggest improve your store with cheap items and earn cents/lose until your store gains traffic and then list hot products. good stores sell hot products and no traffic stores most likely wont sell the same product even for cheaper.
to find products, at the begining, try to find item in which you can compete with as much as possible:
2)number of people selling the item VS the ones who sold is not ridiculos
3)if its an item with many sellers, at least see 1 person with lower feedbacks than you who sold it
4)products with sale through of 50%+ (put upc/title/ean w/o 0 in your market research software
*list the same item like the seller you are looking at if you can put a competive price vs him and vs the other sellers
*list similar other item pretty much same specifics using the keywords of the item you are looking at make sure no mistakes in title