cut (one's) teeth

Translations
набраться опыта
He cut his teeth on small projects before managing a large team.
Он набрался опыта на небольших проектах, прежде чем управлять большой командой.
Definitions
To gain initial experience or learn the basics of something, often in a particular job or activity, usually at the beginning of one's career.
Words
tooth

noun
зуб
cut

verb
резать