If you reported zero inventory at the end of 2017, then it is already deducted and there is nothing you need to do in regards to the inventory.
As for reporting the end of the business, (1) is this a Sole Proprietorship (self employed)? Or is it a Corporation? (2) Were you depreciating any "assets"? If so, on your 2017 tax return, did you indicate that you sold those "assets"?
