initiative vs first step

initiative and first step both are nouns.

Word	Noun	Adjective	Verb	Adverb
initiative	Yes	Yes	No	No
first step	Yes	No	No	No

As nouns, initiative and first step are synonyms defined as:

Other synonyms of initiative include opening, opening move.

initiative (noun)	first step (noun)
the first of a series of actions	the first of a series of actions
readiness to embark on bold new ventures

initiative (adjective)	first step (adjective)
serving to set in motion