starting point vs first

starting point and first both are nouns.

Word	Noun	Adjective	Verb	Adverb
starting point	Yes	No	No	No
first	Yes	Yes	No	Yes

As nouns, first is a hypernym of starting point; that is, first is a word with a broader meaning than starting point:

Other hypernyms of starting point include beginning, commencement, get-go, kickoff, offset, outset, showtime, start, starting time.

starting point (noun)	first (noun)
earliest limiting point	the fielding position of the player on a baseball team who is stationed at first of the bases in the infield (counting counterclockwise from home plate)
	the lowest forward gear ratio in the gear box of a motor vehicle; used to start a car moving
	an honours degree of the highest class
	the first element in a countable series
	the first or highest in an ordering or series
	the time at which something is supposed to begin

starting point (adjective)	first (adjective)
	preceding all others in time or space or degree
	highest in pitch or chief among parts or voices or instruments or orchestra sections
	ranking above all others
	serving to begin
	serving to set in motion

starting point (adverb)	first (adverb)
	before anything else
	prominently forward
	the initial time
	before another in time, space, or importance