The First Rule of Adventuring (Cruxverse #1) by Vichet Ou

SPFBO6

He was just trying to be polite. Asmund Alefson is a professional adventurer who hates his job. Silga Goldenfield is the chronically-kidnapped princess that he accidentally inspires to become an adventurer. Unwilling to dash her dreams, and because dead princesses result in low-or-no reward, Asmund reluctantly takes Silga on as an apprentice. Little do they know, her life choices have run afoul of more than a few dastardly schemes, as an old enemy of the Norlanders waits in the shadows, and a very strange goose follows them around from job to job. The First Rule of Adventuring is a Pratchett-esque comedic fantasy adventure set in the Cruxverse, where music is magic, no one fights werecreatures for free, and even the Composer Gods have to pay rent.