When started out I changed my business plan a few times until I found our Niche. Do you have any hobbies or enjoy certain things? Can you involve you business with those in any way? If so you may actually enjoy the work you do.
If you sign up here with inventorysource you can view sample catalogs from various suppliers. Do some research on average retail prices (Not the MSRP) and then compare them to the wholesale price to see what Net profit would be for the products you would like to sell.
Now you have to think about how frequently you would sell such a product. Can you sell more than what your overhead business costs are? Overhead is 3rd party expenses such as: inventory source, 3rd party plugins, hosting provider, banking fees, etc. Only when you can stay above that amount will your business be successful.