Task: I forgot to add many details about my wife like surname and email id  while saving her contact in my contact list, so edit this contact and mention full name Clara Wagner, add email id clarawagner98b@gmail.com in the Phonebook app.
Steps:
Click on the Clara contact to view the edit option of this contact.
Click on the edit icon at the top of the screen to edit this contact.
Click on the Surname section to set the surname of this contact.
Type Wagner in the surname section to set the surname of this contact.
Click on the Email section to add the email address to this contact.
Type clarawagner98b@gmail.com in the email section to add this email to this contact.
Click on the right tick icon at the top of the screen to save the changes in this contact.