Supply Chain Management- Supply Chain?

I have to do a project in which I have to create a supply chain. I don't know where to start and how to research different tiers of suppliers and customers. I've decided to do a supply chain for UnderArmour, howver I don't know where to look for its suppliers and customers. I've googled this but haven't found much valuable information. Does anyone know what website I should look at to find this information?