To change your displayed first name in Nectar, Navigate to your profile in the bottom left corner and go to Personal Information.
Under your profile picture, you will see a First Name box and a Preferred Name box.
Fill out the Preferred Name with how your want your name to display in Nectar. This will update across Nectar to be your "first name"
If you need additional information changed on your profile, please contact your company admin/HR department for assistance.