You will see:

Put a check mark in the box for the User Group Collaboration session you want to attend, as indicated, and press Register, and it will take you to:

Fill in your First Name, Last Name, and Email Address, and press Submit, and you will see:

You have now registered for both tracks, and as indicated, you should soon receive two email messages:

Here is one of those email messages:

Note you have a Unique URL for that User Group Collaboration Session, and you should not forward that email to anyone else. If they want to attend, have them go to http://snipurl.com/apcugwebinar and register themselves.
To install the necessary plugin, and make sure your computer is set for attending the Virtual Conference, you can click on the last link in your email message, or this one here.
The night of the User Group Collaboration session click the Unique URL on the message it sends you when you register. If possible please wear a headset with a microphone. If you don't have one, then please leave you microphone muted except when you are talking, to avoid a feedback echo with disturbs everyone else.
If you want a preview of the interface you will see, and how to control it, you can watch this PowerPoint presentation (PDF) any time you want.