Wood Storage can be found on Home Island, and will always remain there. You will need to complete the "Collect logs and sticks" quest to unlock it.
Upgrading your Wood Storage will increase the number of slots you have for storage for all items.
It can be upgraded 9 times throughout the game, with each upgrade requiring a different set of items.
For more information on upgrading your Wood Storage, check the guides we have posted to our official Facebook group and Discord channel.
To learn more about building, check out the Crafting Stations section!