20-24 is more suitable, so the height and weight of 180 can be controlled between 140- 160, and 166 is slightly overweight.
Fat loss and muscle gain are not completely independent processes. You can lose fat while gaining muscle.
There is no lazy way to directly convert fat into muscle except exercise.
So far, the best post I have seen is this "secret book of the strongest person in history: the record of a 90-day fat transgender"
It's very detailed. It will definitely help you after reading it.