Helloo Lui Chun Ting, good you planned to stay. look sales will come be patience, you need to upload many more images, review takes atleast 7 days, if you upload everyday two pictures then after the seventh day every day you will have images online. when your portfolio grows then for sure you will have sales.
Anyways here comes your first sale, Happy, many will come, upload, take part in blogs, forums, this is the best marketing strategy, people will see your portfolio and you will get more sales. Oh I think its a big lecture anyways congrats on you first sale.