Go to My Hub > My Roster. It has two tabs, Competitors and Coaches. Click Add and enter:

• First and last name, exactly as they are registered with your sanctioning organization.
• Gender - this must match the levels you will enter them in. Getting it wrong is the single most common reason an athlete cannot be registered.
• Date of birth - used for age-based levels.
• Organization number and level for each organization you compete under.

You only do this once. The roster carries forward from event to event and season to season.