The phrase "Get a life" is an idiomatic expression often used as a colloquial and somewhat informal way of telling someone to find or pursue more interesting or meaningful activities, to stop being preoccupied with trivial matters, or to encourage them to have a more fulfilling existence. It can imply that the person should focus on their own life and stop being overly concerned with others or with insignificant issues.
https://en.wikipedia.org/wiki/Get_a_life_(idiom)
Example:
Person A: "I can't believe she spent the whole weekend just watching TV. Doesn't she have anything else to do?" Person B: "Come on, she really needs to get a life and find some cool stuff to do instead of being glued to the TV all the time."
Example 2:
You guys should just stop moaning and get a life!
Example 3:
Person A: "Why does John always meddle in other people's business? He's always giving unsolicited advice." Person B: "Yeah, he seriously needs to get a life and stop worrying about everyone else's problems."
Can one use 'Trouve-toi une vie !" ou 'occupe-toi de ta vie ' ?