Learn the Ropes
DEFINITION: If you "learn the ropes," you learn how to function in a given environment.

EXAMPLE: I'm sorry, Mrs. Johnson, but I made a mistake on your order. I guess I'm still learning the ropes.
"Thank you so much for the polishing suggestions! I was not impressed with the work done on the résumé in the past. This looks so much better! "
Marcia Veatch
Iowa City, Iowa