Sharp Sharp

I am Cecil Nelson a communications officer living in the UK but originally from Sierra Leone, my country Sierra Leone has a population of just 8 million people with about 1 million 5 hundred thousand to 2 million living in the capital Freetown. We do not have any online marketing like Ebay or Wish. I want to be able to give people a platform to browse through and buy bags, shoes, sneakers, perfume, watch, vape, phones new and used, ipads and tablets, projectors,viedo games etc. to name a few. I want an app to sell things on just like Wish app, ebay and amazon. Its for my country back home Sierra Leone, but i just want a platform that I can display my items with online bank payment and also collection in person because online banking is not common in my country and just a handful amout of people will be able to pay online. The buyer can be able to show interest on an item or product and then have a grace period of 48 hours to collect it at our office. We can also do delivery to well known institutions or individuals if we can communicate via email, mobile, whatsapp, text or direct call. i would like to know what it will entail to get an app set up that will be easily downloaded in playstore and then easy to use with some registration details.