If you are currently in the United States and you entered with a visa, you can file for Adjustment of Status based on your marriage to a US citizen. You will need to prove that your marriage is legal and in "good faith," meaning that you married for love and not for immigration purposes, and that you are not ineligible for permanent residency (green card) due to any criminal or immigration violations.
If you are outside of the United States, it will be a two-step process. First, your spouse will need to file the family petition to prove your marriage is in good faith. After that is approved, your case will be transferred to the Department of State where you will go through "consular processing." The final step will be attending an interview at the US Embassy nearest to you where a consular officer will determine if you are eligible for permanent residency. If your visa is approved, you will enter the United States as a permanent resident.
If you are a US citizen, there are two ways to bring a fiancé to the United States. The first is the fiancé petition, which requires a showing that you are in a good faith relationship, that you have met in person at least once in the two years before filing, and that you plan to marry within 90 days of their arrival into the US. Once that petition is approved, your fiancé will attend an interview at the US Embassy in their home country where a consular officer will determine whether they are eligible for the visa. Once they arrive, you will have 90 days to get married and can then file for a green card at any point after that.
The second option is to get married first and to complete a family petition. You would need to file a family petition to prove your marriage is legal and in good faith. After that is approved, your case will be transferred to the Department of State where your spouse will go through "consular processing." The final step will be for your spouse to attend an interview at the US Embassy where a consular officer will determine if they are eligible for permanent residency. If the visa is approved, your spouse will enter the United States as a permanent resident.
If you are a permanent resident, the only option available to you is to get married and complete the family petition and consular processing. Permanent residents (green card holders) are not eligible to submit fiancé petitions.
US Citizens can petition only for certain family members, including spouses, parents, children, and siblings. If you are the spouse, parent, or unmarried minor child (under 21) of a US citizen, they can file a petition for you and then you can immediately apply for permanent residency (green card) assuming you do not have any grounds of inadmissibility that would make you ineligible for that residency. However, if you are the adult child, married child, or sibling of a US citizen, then there will be a wait before you will be eligible to apply for residency. The United States limits the number of green card available to those categories each year, meaning there is a backlog and a waitlist. In order to get on that waitlist, the family petition must first be filed.
In order to study in the US full-time, you must obtain an F1 student visa. The first step in obtaining this visa is applying to and being accepted into a school that admits international students. Once you have been accepted, the school's Designated School Official (DSO) should provide you with the necessary paperwork for obtaining the actual visa. With that paperwork in hand, an experienced immigration attorney can assist you in completing the visa application and preparing for your visa interview at your local US Embassy. At the interview, you will need to show that you intend to study at your designated school, that you have the funds to cover all tuition and associated costs, and that you are not abandoning your residence in your home country.
In order to apply for a US passport, you must be a US citizen. If you are a native-born or naturalized US citizen, you are eligible to apply for a passport through the Department of State. Most post offices service as passport offices, where you can submit your passport application and the necessary documents, including original documents proving that you are a US citizen (i.e. birth certificate or naturalization certificate). If you obtained citizenship through a parent, you may also want to apply for a Certificate of Citizenship from US Citizenship and Immigration Service (USCIS). This Certificate can be used as your original document proving your US citizenship.
Technically, no. There is no immigration process where you can be required to have an attorney assist you. However, the risks in not hiring an attorney can be high. An experienced immigration attorney can ensure not only that you are eligible for the relief or benefit that you are seeking, but that the process will be done quickly and correctly the first time. Submitting incorrect documents or failing to submit required documents can result in timely delays or even denials. If an application is denied by the US Citizenship and Immigration Service (USCIS), the applicant will risk being placed into removal proceedings and having to go in front of an immigration judge to defend themselves from deportation. Due to the high stakes, and the importance of having an application completed correctly the first time around, it is always best to consult and work with an experienced immigration attorney.