Even a poor person could one day live at Pennsylvania Ave.

Is poor person considered a proper noun cause it names a specific person.

No, it is a common noun. Now if it had been "...Sam Jones, a poor person, may someday live ..." Sam Jones would be a proper noun, but person would be a common noun used as a describer.

No, those are not proper nouns, they are not the name of anyone or thing.

no it has to be a specific name

In the sentence "Even a poor person could one day live at Pennsylvania Ave.," the term "poor person" is not considered a proper noun. Proper nouns specifically refer to the names of particular people, places, or things. Proper nouns are always capitalized.

The phrase "poor person" is a common noun because it doesn't refer to a specific individual, but rather to a general category of people who are financially disadvantaged. Common nouns are not capitalized unless they begin a sentence.

To identify proper nouns, you can look for capitalized words that refer to specific individuals (e.g., John, New York, Mount Everest) or unique titles and names (e.g., The White House, Coca-Cola). In contrast, common nouns refer to general categories and are not capitalized unless they start a sentence.