Workbench
The Workbench is the prerequisite for almost everything. Without one, gathered materials are inert — you can pick up Leaves and Small Logs and Stones, but you can't turn them into anything. With a Workbench, you have a craftable, placeable kitchen for the island's entire material economy. It is, in every meaningful sense, the most important item you'll build.
Crafting
Recipe: 2× Stone. Stone comes from Rock Smash (taught by Hitmonchan). This creates an interesting progression dependency: to build the Workbench, you need Hitmonchan befriended. To befriend Hitmonchan, you need to set up an Exercise Resting Spot habitat. To set up that habitat, you need other materials. The Workbench is never the first thing you do, but the steps toward it are the tutorial.
Placement Notes
Workbenches can be placed anywhere on the island, and you can craft multiples once you have the materials for them. A practical approach is to place an early Workbench near your starting area and a second one closer to whatever biome you're currently developing — this cuts travel time significantly during active construction phases. Chef Dente sometimes gives quests that reference the Workbench's location, so keeping one near the social hub area has advantages beyond pure efficiency.