Totally be IC new to this, the phrase ‘this is my first time in Anvil’ is really good for indicating such.
But how inexperienced your characters are might not relate to the IC age of your house.
In some ways it might be easier to come from the ancient house of Tall Stag, and IC not be brilliant on the history. Than create a new house (because not knowing history is easier to explain than not knowing something your characters did.)
So Oath, honestly pretty much anything goes. My House has “Destroy Barbarians and retake the Barrens” as our oath. I’m sure it’s a little more poetic (but not much) but it’s been a while since I used it. By contrast my sect (which is more a errantry group) has:
"In the darkness of the past, we seek the shadows of glory.
Searching for the shadows cast by lights long since past.
Shadows cast by Dawn’s greatest, of queens, of champions.
Yet despite of how bright their deeds once were.
Across the ages, shadow has faded, merging with darkness.
From those shadows that we can still wrest from obscurity.
Let legends be reborn, their deeds again to echo across the land.
From their stories, others may be inspired to burn brightly.
Learning lessons of past tragedies to avert the crisis of the future.
Let the knowledge of the past be a spark for even greater legends
So are born new lights, to cast new shadows on the future."
A good oath, is one that encourages you to do things. Work out what your group is about and make that the focus of your oath.