cut teeth

[cut teeth] {v. phr.} 1. To have teeth grow out through the gums.

The baby was cross because he was cutting teeth.

2. or [cut eye teeth] {informal} To learn something very early in life; gain experience; start by learning or doing. - Used with a possessive, usually used with "on".

The professional ball player cut his teeth on a baseball bat in the sandlots.

Mr. Jones's company is building the new Post Office in town but Mr. Jones cut his eye teeth as a carpenter.