I think most people here will be grinding their own coffee per batch. It's typically step 1 or 2 when getting into the hobby, the other being buying better coffee.
That being said, if you do have pre-ground coffee try to use it as quickly as possible as it will lose flavor much faster than whole beans. Store it in a dark, air-tight container.
That tin box you have was originally used for loose leaf tea and is widely available if you want more