At the World Market, you can browse items for sale from Trademasters all around the world! You can even visit their islands and add them as friends!
The World Market is the dockyard on the leftmost part of the island. You will need to reach level 12 before you can clear the land leading to it and fully repair the World Market for use!
Once inside, you can scroll through other Trademasters’ listings and find the goods you need. The boards display one item each player is selling—tap that item to see all the goods they have for sale.
1) Each sale board displays the player’s name and a preview of their market. Tap any sale to visit this player’s market and purchase items from them!
2) Tap the “X” to exit the World Market and return to your island.
3) Swipe the screen to scroll through more available sales!
1) Tap any available item to purchase it.
2) When an item reads “Sold”, it is no longer available for purchase.
3) Tap the “Visit” button to visit that Trademaster’s island!
The above is Quoted in part or full directly from the Official Paradise Bay FAQ