Abstract noun.
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Common
Yes, the noun 'kindness' is a common noun, a general word for the quality or state of being gentle and considerate; a word for any kindness of any kind.
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
it's a common noun. a proper noun would be Spider-Man.
Pencil proper or common noun
Proper noun or common noun
Kindness is an abstract noun, as it represents a quality or state of being rather than a physical object.
The noun cassette is a common noun.