"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Common
Yes, the noun navigator is a common noun, a word for any one who navigates or any instrument used to navigate.A proper noun is the name of a person, place, thing, or a title; for example:Henry (1394-1460), third son of King John I of Portugal, earned the title 'Henry the Navigator'.Navigator Court, Staten Island, NYNavigator Institute of Technologies, Calicut, India'The Navigator' (movie 1924) starring Buster Keaton
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
The noun cassette is a common noun.
a common noun?
The answer is proper noun. Examples of common noun and proper noun are: Proper noun: Mary Collins Common noun: monkey