With accent marks:
Я́йца ку́рицу не у́чат.
Eggs don't teach the chicken.
The meaning of this proverb is simple: an inexperienced person can not teach anything the experienced one. You can often hear that from parents talking to their children.
Other Russian proverbs
Appetite comes with eating.
Without labor, you can not even catch a fish in the pond.
The eyes are scared, but the hands are doing.
The quieter you go, the further you'll get.
Start taking care of the dress while it's new, and of your honor while you are young.
The apple never falls far from the tree.