Amateur and New kid on block

Amateur noun - A person who regularly or occasionally engages in an activity as a pastime rather than as a profession.

New kid on block and amateur are semantically related In some cases you can use "New kid on block" instead a noun "Amateur".

Amateur and new kid on block are semantically related in beginner topic. Sometimes you can use "Amateur" instead a noun phrase "New kid on block", if it concerns topics such as novice, newcomer, person just learning something, person unskilled in something.