Hi Jaya,
Yes. You have created a shopping cart. But the follow on document for the item is already created.
To know the PO which is created for this cart, login to portal => Employee self services => advanced search => select shopping cart from the dropdown => enter shopping cart number => click search. The shopping cart document will be opened.
Now click select the item (by clicking on the left most square button), click on details button on top of the item. the particular item's details are displayed. go to related documents tab. you can find the PO number there.
If you donot want to PO to be created, then check the SPRO settings.
SPRO => SAP Supplier relationship management => SRM SERVER =>sourcing => define sourcing for product categories . And make necessary settings there as per requirement.
Regards,
Karthik