i have seen u wanted to know how to import a tile and use it.
1st: Download the model and import it at the import manager
2nd: You need to know the path. It should be written somewhere on the page. If not u cant use the tile.
3rd: Double-click the tile you have imported. Use custom path, copy the path which shall be written at the page and paste it into the tile.
4th: They usally say which tile it will replace. Find the tile it replaces, and add it with the Advanced>Modify Tileset at the menu at top of the world editor. Then it should work.