Hello There,
If this is a new account and no inventory upload is yet performed, you would not see devices on the portal.
You may want to look at below resources on how to go about "Creating Your Initial Inventory"
http://www.cisco.com/c/dam/en/us/td/docs/net_mgmt/inventory_and_reporting/User_Guides/SNTC_Portal_User_Guide.pdf
https://www.cisco.com/E-Learning/bulk/subscribed/SNTC_vods_EN/index.html
Regards,
Suchita