yu can sell t-shirt. i see selling t-shirt is veru simple and rate benifit in usa. and you can run ads to increase products sold. you can add me in skype, i can told you more. my skype: nguyennga32016
I think you should be more specific which product are you willing to sell online. anyway i can give you my experience on selling products in my own city.
You should post on different online classified websites where you can target your city region people and create pages in different social media sites about your products and try to me more active. join in different social media groups which are related to your product and the city and don't bang with your adds the admins may block you. so try to be more engage and active in groups and sell your product as a third person who already used your this may give more results and more over now a days people will research on different sites about a product and if you don't have any website then you have to loss more relevant customers. Try this Boomer Marketing App which is more useful for a small business people like us to create a website for free with out any technical and coding knowledge from mobile itself. i found this App more useful try this may help you in giving website links in all the classified websites and people who show in terest
here is the link.. https://goo.gl/n5D9w3