good luck vs destiny

good luck and destiny both are nouns.

Word	Noun	Adjective	Verb	Adverb
good luck	Yes	No	No	No
destiny	Yes	No	No	No

As nouns, destiny is a hypernym of good luck; that is, destiny is a word with a broader meaning than good luck:

good luck: an auspicious state resulting from favorable outcomes
destiny: your overall circumstances or condition in life (including everything that happens to you)

Other hypernyms of good luck include circumstances, fate, fortune, lot, luck, portion.

good luck (noun)	destiny (noun)
an unexpected piece of good luck	an event (or a course of events) that will inevitably happen in the future
a stroke of luck	the ultimate agency regarded as predetermining the course of events
an auspicious state resulting from favorable outcomes	your overall circumstances or condition in life (including everything that happens to you)