You will have to answer this question yourself. Every environment has its own idioms and slang terms, and we don't know what part of the world you live in.
cry for the moon
Some examples of idioms in "Divergent" include "jumping off the deep end," "barking up the wrong tree," and "walking on eggshells." These idioms are used to convey deeper meanings or emotions within the story.
Some common idioms about music used in everyday conversations include "to be in tune with," "to strike a chord," "to face the music," "to call the tune," and "to be music to someone's ears."
Wherever people lived -- people have always used idioms and slang.
The idioms of languages give a double meaning at times. It also may add some humor to a situation. "I had a dog once that was dumb as a brick."
There are many idioms and phrases for 'on the back burner'. Some idioms and phrases for 'on the back burner' include 'pushing aside' and 'procrastinating'.
Yes, every language has slang and idioms.
Some idioms in the book "The Gods Are Not to Blame" include "cut off the head to cure the headache" and "a leopard cannot change its spots." These idioms are used to convey certain lessons or truths about human nature and destiny.
"Idioms for Being Afraid", "Idioms for Being Angry", "Idioms for Being Happy" are some examples of idioms found in the book "Found" by Margaret Peterson Haddix.
When the English language developed. People have always used idioms and slang in their speech.
Here is a link to some idioms. You can pick the "non-common" ones for yourself -- some people have heard certain idioms a lot and others have not heard the same ones, so you'll need to decide that part.