Such a person is a patriot.
Someone who serves food is called a "waiter" or a "waitress" and sometimes called "staff".
IT IS CALLED CONSUMER!
A person who serves of his or her own free will is officially called a volunteer.
The chief city of a country is called the capital city. It serves as the political, economic, and cultural center of the country and is usually where the government is headquartered.
peer
barista is the official name of someone who serves coffee
It is called double-fault when you miss both of your serves. You lose a point then.
Such a Web Page is called a Blog
A steward or stewardess, some times called 'flight attendants'.
It's called a process server yo.
lunch lady or cafeteria lady