Here the author refers to himself by his "heart" to emphasize his feelings. Alternate translation: "I determined" or "I applied myself" (See: [[rc://en/ta/man/translate/figs-synecdoche]])
The words "madness" and "folly" share similar meanings and refer to foolish thinking and behavior, respectively. (See: [[rc://en/ta/man/translate/figs-doublet]])
The author says learning wisdom and madness and folly is as useless as trying to control the wind. See how you translated this in [Ecclesiastes 1:14](./14.md). Alternate translation: "as useless as trying to control the wind" (See: [[rc://en/ta/man/translate/figs-metaphor]])