@JAJ
You may have attended past Inspires where you pre-registered for breakout sessions. Inspire 2018 breakouts will be first come first serve. Here's a link to Leah's post about breakouts this year:
https://community.alteryx.com/t5/Inspire-2018-Buzz/Inspire-2018-Breakout-Sessions/m-p/155635#M158
On a related note, the Alteryx Inspire 2018 app is available on the Google Play and Apple app stores. There should be a communication soon with more information about how to get it set up for the conference.