In order to obtain US citizenship, you must marry a US citizen in the first place. Your fiance must file a "fiance visa" which will award you temporary status in the US. You must then apply for permanent residency via the I-485 application (greencard.) Then, you must wait an indefinite number of years until you are eligible by law to become a naturalized US citizen.
You would begin with an attorney to answer this type of legal question.
You should visit the United States Citizenship and Immigration Service (see the area titled "Related Links" further down on this page, below this answer area).
Did you come to the United States of America on a Fiancee' Visa, and then you married with the permission of USCIS? In light of the fact that many people want to live in the USA there is often a desire to marry a US Citizen, obtain citizenship, and then divorce the spouse. There have been cases where US Citizens (both men and women) solicit a fee to marry a foreigner in order for that person to ultimately become a US Citizen. Of course, those marriages-for-a-fee are illegal and result in criminal sanctions.
All of those things will be addressed at the United States Citizenship and Immigration Service webpage. It is a fairly expensive process at around $2,000 (or more) and it takes about 5 or 6 years before it is finalized.
The applicant must be age 18 or older at the time of filing N400.
The applicant is a permanent resident ("green card" holder) with valid green card for a period of the past 5 years. If married to U.S. Citizen you may apply after 3 years with valid green card. One exception prevails - if an applicant has served in the United States armed forces during war, that individual may obtain US citizenship without first becoming a permanent resident if they were in the United States upon enlistment into the U.S. military.
Green card holder
Citizenship is not acquired by marriage. After 10 years of residency in the Philippines you may request to become a Philippine Citizen or you can be made a citizen by act of Congress for special and outstanding contributions to the Republic of The Philippines.
She would need a UK work visa.
You must live in France for several year while applying to be a French citizen.
You can but be aware, that the UK citizen cannot legally change their status while in the US. It depends on where you both want to live. If the US citizen wants to come back to the UK, a marriage visa is needed from the British Embassy in the US. However if the UK citizen wants to live in the US, they will have to go back to the UK and the US citizen will then need to file the I-130. Until it comes through you cannot live in the US, but will have to wait in the UK.
Your spouse has to sponsor you for immigration to Mexico.
No, as of current regulations, citizenship in Barbados cannot be obtained through a grandparent. Citizenship is primarily based on parental lineage or by birth in the country. You may explore other avenues, such as through investment or residency programs, to become a citizen of Barbados.
If you marry your British boyfriend, he does not automatically become an American citizen, and you do not automatically become a British citizen. You both have the right to live in each other's country, but you must file paperwork to do so. Citizenship is not automatic.
yes just live there
There is no requirement for you to file anywhere else. The marriage is legal everywhere.
Get a working visa, and use it. Apply for and get permanent residency.
A marriage immigration visa, also known as a spouse visa or a marriage-based visa, is a type of visa that allows a foreign national to enter and live in a country based on their marriage to a citizen or a permanent resident of that country. This visa is granted to individuals who are married to someone who is already a citizen or permanent resident of the country they wish to immigrate to. The purpose of this visa is to enable spouses to reunite and live together in the same country.
Too broad a question - must be narrowed down tpo be answered here