At a glance you have all the appointment information visible: Date, time, brands attending, season, location, sales rep(s), description, contacts, and activity. 

Contacts - send a reminder individually, or to all contacts listed that are attending the appointment. Note that once a reminder is sent, the button will show that a reminder has been sent. 

Activity - Once an appointment has been created, any changes to the appointment will be logged under activity. 

To make changes to the appointment itself, click "edit"