The simplest way to log in to your event in ClearEvent is to go to https://www.clearevent.com and click the Sign In link at the top right of the screen:
You be prompted to Sign In with existing ClearEvent Account, or you can click the Need an account? SIGN UP link at the bottom of the dialog if you don't already have an account.
This will take you to the My Events list where you'll be able to see a list of all the events you are attending.
Alternately, you can navigate directly to the app using: https://app.clearevent.com