: "The baby is crying because she’s cutting her first tooth". Figurative Idiom: "Cut one's teeth on"
Literally, it refers to the process of , specifically when a baby's tooth first begins to push or "break" through the gum line.
As an idiom, to something means to gain your first experience or learn basic skills in a particular field, often through a specific project or job. It suggests a foundational period of learning that prepares you for more advanced work.