Your portal:
https://infraworks360.autodesk.com/portal

What’s the difference between Infraworks and Infraworks 360? Infraworks 360 is the ‘big brother’…
Autodesk InfraWorks 360 Questions and Answers | InfraWorks 360 | Autodesk Knowledge Network

Hotfix:
Autodesk InfraWorks 2015 Model Builder Security Hotfix | InfraWorks 360 | Autodesk Knowledge Network

Activation:
To activate Autodesk InfraWorks 360 | InfraWorks 360 | Autodesk Knowledge Network

How to activate InfraWorks 360 modules | InfraWorks 360 | Autodesk Knowledge Network