Cut your teeth on something
Definition 1 of 1
Pro Tip 1/3Career Start
Used when talking about the first steps taken in a professional career or field. 
She cut her teeth at a small tech startup before joining a major corporation.
Pro Tip 2/3Skill Development
Speaks about the early stages of developing and honing skills in a particular activity or hobby. 
I cut my teeth on acoustic guitar before I ever played electric.
Pro Tip 3/3Idiomatic Origins
Refers to its figurative meaning, not related to literal teeth cutting such as during infancy. 
Many chefs cut their teeth on basic techniques before mastering gourmet cooking.