Tremere/ranks
Rank is taken very seriously within a Chantry. For a full discussion of rank and privilege within a single Clan Tremere Chantry, see pages 26 to 29 of the Tremere Clanbook. Rank in general is discussed in the first part of chapter 2 (p 25).
It isn't everything: only the Regent can directly command another member of her Chantry to act. However, woe unto the apprentice or initiate who disobeys so much as a hint from the Chantry's Primogen. And if the Regent has assigned you as assistant to another's task, obey it.
Rank governs a lot of the public things within the Clan. Tremere will enter an official Elysium meeting in Rank order, and leave in Rank order. If two Tremere meet publically, the lower ranked gives deference to the higher.
It also governs private matters. And effective rank inside the confines of the Chantry walls may differ from nominal rank - a lower-level Apprentice who repeatedly achieves for the Tremere may earn more respect than an idle higher level Magus.
Within a Chantry: Apprentice of the First Circle Usually a new Tremere. Demotion to the First Circle would be a hideously embarassing event for an older Tremere. An Apprentice of the First Circle is usually under strict oversight; reporting to the Regent on a weekly basis, frequently living in the Chantry, and often being given assigned tasks. Most apprentices of the First Circle are studying their first rituals, learning the basics of Thaumaturgy (almost always the Path of Blood), and learning how to be Kindred. Once an Apprentice of the First Circle has mastered the basics of being Kindred and Tremere, understands the Oath and the Traditions and can be counted on not to egregiously breach the Masquerade or embarass the Clan, they are promoted.
Apprentice of the Second/Third Circle