You'll be selecting a family, and the family you've selected will become "nobility or aristocracy," whichever is relevant to your pledge package/title you hold going into the game later. You can start at fifteen or become one of the parents as an NTC if you wish. Caspian answered similar questions asked in the past, they're a bit old but it is still relevant. [Source - Caspian in the CoE Discord (10-22-16) and (10-23-16)]