There are several places for you to view your Contacts:
Go to the Contacts page to view all of your contacts
Go to the Clients and Contacts page within a lead or shoot to view all of the contacts for that particular lead or shoot.
To edit a contact while viewing the list of all contacts, click the contact's name or the 3 dots at the end of that row, and then click the "Edit" button.
To edit a contact while viewing the contacts from within a lead or shoot, click the "Edit" button underneath the contact.
While editing a contact, you can edit:
Their profile photo.
Their name, saved as first and last name.
Their company name.
Their username, which is what they'd use to login to their client portal.
Their contact details (i.e. an email, a phone number, etc.), or add a new contact detail.
Their custom contact details, which are fields you can create to record other pertinent information about your clients (i.e. their birthday, anniversary, etc), or add a new custom contact detail.
Their address.
Clicking the 3 dots will also allow the options seen above.