To Add a Person's details when you are first adding a Person in Brivity, fill out the Add a New Person form and fill in their basic info in the fields that are available. This will create the Person with the information you fill out. To get this started, click the + next to People.
After the initial setup, you'll be brought to the Person's Details page, where you can thoroughly fill out the Person's information. When you're finished, click Save Details.