The best way to free up space in your storage is to complete orders on the board to get rid of some of the items you have.

It is also possible to directly sell items from your storage. To do this, open the storage, tap the item you want to sell, select the amount using the "+" and "-" buttons, then tap "Sell".
Sell items
You can also upgrade your storage to increase its capacity:
  1. Tap the barn icon in the bottom left corner of the screen
  2. Tap "Goods"
  3. Tap "Upgrade" on the left side of the screen.
Storage Upgrade