Answer:
don't sweat the small things
Explanation:
the phrase is pretty much telling you not to worry and panick about small things
What is it that you need help with?
Answer:
A combination of a verb and an adverb or a verb and a preposition, or both, in which the combination has a meaning different from the meaning of the words considered separately : "Catch on " is a phrasal verb meaning of understand.
C situational irony it the answer