Market Place

The marketplace is situated right beside your Campsite. Here you get to shop for clothing and Furniture from various merchants that are selling there in rotation. You'll also get a hold of Isabelle in this area (the animal in the tutorial), and chatting with her will let you check and have her cover again previous tutorial lessons. Other than that, she can also let you check both your timed and Stretch Goals.

Aside from buying stuff in the market place, you may also sell items from your inventory with any of the traders present there. Just talk to them, and an option will be available, allowing you to sell Furniture or clothes for Bells.

On the other hand, to buy stuff from these merchants, what you need to do is to approach the displayed items instead. As the window pops up, you may inspect closely what you are about to buy and see info about it and its cost -- before you confirm if you'll buy it or not.

Shops

At the current version of the game (v 1.1.15), there are currently three present shops in the marketplace. One for clothes, run by the Able Sisters, a Furniture shop run by Timmy and Tommy, and a foot gear shop by Kicks. These shops usually display a selection of 3 different items, and renews their selection every 3 hours.

Merchants in the Marketplace

Able Sisters' Shop

Mabel, Sabel and Labelle (watching over their shop in rotation), sell you a wide variety of clothes to wear. The selection of displayed items change every after 3 hours (as well as the shopkeeper). There will be 3 items sold at any given time, consisting of clothes that include headgears, shirts, dress, and pants.

Kicks Shop

Kicks is a skunk that specifically sells socks and footwear. His shop usually swaps out with the Able Sisters' shop every 24 hours. He runs his shop during the whole duration and swaps out his merchendise every 3 hours.

Timmy and Tommy's Furniture Shop

Another Shop is situated at the right of the marketplace, where you may get a hold of a selection of unique Furniture aside from those that you can usually Craft by yourself. The shop is run by Timmy and Tommy, and are always available in the game (they do not swap out with other merchants at least for the time being). Their selection of sold items (as well as the shopkeeper) also refresh every 3 hours.