Affiliate functionality is not enabled by default on your TutorCruncher account. To enable it, navigate to System > Settings > People and Activity > People where you can tick the checkbox for Use Affiliates.
The People panel, with the Use Affiliates checkbox highlighted.
Note: Changing this setting requires the 'Edit Company Settings' or 'Edit Branch Settings' permission on your Administrator profile.
Creating an Affiliate
Once 'Use Affiliates' is enabled, go to People > Affiliates and select Create New Affiliate, where you can fill in the Affiliate's details before clicking Submit.