Little off-topic for this channel, but an anecdote related to this:
In one game I ran, a young squire NPC joined the party because she was determined to bring one of them to justice, but was talked into helping him finish his quest and save people.
At the start of her journey with them, she was determined to swear an oath of devotion to her order. But as she journeyed with the group, often acting as a moral compass and touchstone for them, and speaking with the people they rescued- or captured- and gained worldly experience, by the time she returned to her order to swear her oath, she didn't swear an oath of devotion- but redemption.
She started off trying to earn one oath, and by level 3, had discovered the oath that was truly calling to her.
But this is very DM dependent, and something you'll need to chat with your DM about if wanting to try and play with what your oath means to your character at low levels and if you actually end up changing your mind on what oath they'll take (which may depend on which subclasses you actually have access to)