How do i add parent information to a teenage volunteer profile so that when a new volunteer fills out their profile, it creates a parent relationship and contact as well. I am using Profile-Create Mode to allow the data input on our website.
You would need to created an extension using civicrm hook 'hook_civicrm_postProcess' which gets invoked when a civicrm form is submitted as you want the actions to be taken upon profile submission so this should work for you. In the hook you can create the relationships through the API call.
Detailed documentation on hook.
Hope this helps.