Does the inventory have a way to show what has been purchased which reduces my inventory?

Hi there, Deborah. 

Yes, you can run an Inventory Valuation Detail that displays the current quantity and cost of each item along with its sales price.

Here's how:
 

1. Navigate to Reports menu.
2. On the search bar, type in Inventory Valuation Detail.
3. From the Report period dropdown, select All Dates.
4. Select Run report.

Moreover, you can check out this article for more details to have an accurate count of your inventory: Fix negative inventory issues in QuickBooks Online.

If you need further assistance, feel free to comment down below and I'll be here to assist.