newcomer vs fledgling

newcomer and fledgling both are nouns.

Word	Noun	Adjective	Verb	Adverb
newcomer	Yes	No	No	No
fledgling	Yes	Yes	No	No

As nouns, newcomer and fledgling are synonyms defined as:

Other synonyms of newcomer include entrant, fledgeling, freshman, neophyte, newbie, starter.

newcomer (noun)	fledgling (noun)
any new participant in some activity	young bird that has just fledged or become capable of flying
a recent arrival	any new participant in some activity

newcomer (adjective)	fledgling (adjective)
	(of a young bird) having acquired its flight feathers
	young and inexperienced