There are lots of eCommerce stores out there that sell clothing. For example, Fashion Nova sells both new and used clothing. Zappos sells new and used clothing, as well as shoes. But one of the best places to buy cheap brands online is Depop.
You can also go to Shein. It is an online clothing store that sells all types of clothing, including dresses, tops, bottoms, skirts, jackets, and accessories. They also sell shoes.