Synonyms and Nuance

As I progress more and more with my Japanese studies, I come across more instances like this where there are multiple ways to describe a concept that, in English, is just one word (or phrase). My question is how do I know which one to use and when? Are there any resources that help with determining the difference in nuance? Or should I just hope that I pick up on it from immersion? Also, if someone could help me know which word to use for the phrase "turn on the AC", I'd appreciate it. App is Obenkyo btw.

by GenderfluidPanda1004