Common nouns are used to refer to general or unspecified entities.

Proper nouns are specific names of people, places, things, or entities. They are always capitalised, regardless of their position in a sentence.

The common nouns in this sentence are 'actor' and 'movies'. 'Tom Hanks' is a proper noun.

'Dogs' is a general noun. It is capitalised because it starts the sentence, not because it is a proper noun.

Proper nouns are specific names of people, places, things, or entities. They are always capitalised, regardless of their position in a sentence.

It should be 'Louvre Museum'.

The two proper nouns are 'The Irishman' and 'Netflix'. The common noun is 'movie'.

The cardinal directions (north, east, south, west) are common nouns in most cases. But they become proper when used with a cultural or political meaning or in the name of a specific location. For example, 'Head south ten miles before turning left' is a common noun. But 'The North and Midwest regions of the United States are suffering a heat wave this year' are proper nouns.

'King Charles' and 'Buckingham Palace' are both proper nouns. All the other sentences have at least one common noun.

The one proper noun is 'England' and the two common nouns are 'Football' and 'sport'.