Training for Ariba is available at training.sap.com. Here is the link for the Ariba curriculum https://training.sap.com/shop/content/successfactors-ariba?url_id=text-g-homepage-sf-ariba
There is also training for Ariba Cloud Overview at the SAP Learning Hub. Access to this training requires a subscription.
If you have further questions about the training, it is best to contact the SAP training support team directly. Contact details for SAP support are available on the training site.
Cheers!
Debbie