amateur vs doer

amateur and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
amateur	Yes	Yes	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of amateur; that is, doer is a word with a broader meaning than amateur:

Other hypernyms of amateur include actor, worker.

amateur (noun)	doer (noun)
someone who pursues a study or sport as a pastime	a person who acts and gets things done
an athlete who does not play for pay

amateur (adjective)	doer (adjective)
engaged in as a pastime
lacking professional skill or expertise