Hi Aditya:
Congrats on your new opportunity. If you're looking for training, here are a few options:
You can get an introduction to Ariba via OpenSAP training recordings. Here's a link to the Introduction to Ariba course: https://open.sap.com/courses/bnar1
There are a variety of programs for Ariba and Procurement available at the SAP Learning Hub. The Hub offers self-paced eLearning versions for most of the Ariba classes. You can identify them by the "e" in the name, for example AR510e is the e-Learning version of AR510. Here's a link to the e-Learning catalog: https://training.sap.com/shop/sap-search?q=*&refine%5Bsolution%5D%5BCloud%5D=Cloud&refine%5Bsub-solution%5D%5BAriba%5D=Ariba
Ariba Procure-to-Pay certification launched in April 2016. You can learn more about the program at this blog: http://scn.sap.com/community/training-and-education/certification/blog/2016/04/20/sap-ariba-has-arrived-with-certification-in-the-cloud-for-ariba-procure-to-pay
Cheers,
Debbie