How does one register there team on FIRSTbase?

Go here:

Read the section that says " How do I join Autodesk FirstBase?"

You need your TIMS contact to register on Autodesk and set it up for the team. After that your TIMS contact will give you a password, and when you register it will ask you for your team specific password. THAT will grant you and your team access to FBADI and enable you to download the software.