Depending on what you are doing in Ariba, there are different ways of connecting with customers.
If you will be exchanging transaction documents (purchase orders, invoices, etc.) with your customer through Ariba, you will have to establish a trading relationship with them first.
If you will be participating in a customer's sourcing event, they must first send you an email invitation. You can access the event through the invitation, or by going to your Proposals by clicking the app drop-down menu in the upper-left corner of the application and selecting Proposals. If your event is not listed on the Proposals page, please see here for troubleshooting steps.
If you are searching for potential business opportunities, you can click the app drop-down menu in the upper-left corner of the page and select Leads to view postings on Ariba Discovery.
SAP Ariba Sourcing