Custom fields can be found in two places.
1. Within any contact profile in your account
2. In your Account Settings
1. Finding Custom Fields in a Contact Profile
Go to any contact profile in your account, or create a new one! Once you are in a Contact Profile, you will then be able to see the Custom Fields section.
To create new ones, select "Manage Custom Fields"
2. Finding Custom Fields in your Account Settings
Go to your Account
Click on your name on the top navigation bar and select "Account."
2. Go to the Settings Tab
From the Settings tab you will be able to click on the Manage Custom Fields button.
For more information on Custom Fields, don't forget to check here!