I may have misunderstood your question, but perhaps this will help:
“Empty” can be used about spaces and containers.
If you want to say that there is nothing in a container or space, you can say:
My cup is empty.
My bag is empty.
The room is empty.
You could add the word “completely”, for emphasis:
My cup is completely empty.
If you are talking about not having something, you can say:
I don’t have any money.
I don’t have any knowledge of Japanese.
If you want to stress that you have absolute nothing, you can add “at all”:
I don’t have any money at all.