This is probably one of the most important questions to ask! imATHLETE calls the participant data section Participant Details. You can get to Participant Details in one of two ways:
From your dashboard, click the Participant Details link to the far right of the event name
From your dashboard, click on the title of the relevant event name
Both take you to Participant Details where you can then access your participant data, which happened to be your question in the first place.