I'm here to assist you today, @CHRISTACOX.

To clarify, may I know if you're using the US version of QuickBooks Desktop (QBDT)?

If so, the purchase order (PO) number will auto-populate based on what you've entered. Let's say you create PO 001, the program will automatically display 002 in the No. field.

Let me show you how:

1. Go to the Vendors menu.
2. Select Create Purchase Orders.
3. Choose the vendor name.
4. Enter the necessary information including the P.O number.
5. Once done, click Save and Close.

I've also added this resource to guide you enter a purchase order in QuickBooks Desktop: Create purchase orders.

Additionally, you may want to learn how to receive inventory with or without a bill in QuickBooks Desktop. 

That should do it. Let me know if you need further assistance in managing vendor transactions in QuickBooks. I'm always here to assist. Have a great rest of the day.