You must be an Account Manager to login and manage your account (this is different than having a Chair/Admin account for one or more of your event sites).
If your subscription allows additional events, Create New Event button displays under Event Information section.
Choose the URL for your new event site
On this screen, you'll provide basic information about your event. Once the event site is created, the URL is NOT editable - so choose carefully. All other fields (Name, Date/Time, Timezone) can be edited later from your Account page or the event site site settings.