Before starting the application process, there are two questions that you should answer first:

1. Are you eligible to apply?
U.S. immigration laws provide a variety of ways for people to apply for a Green Card. The eligibility requirements may vary depending on the immigrant category you are applying under. 

Being Sponsored for a Green Card
Most people who apply for a Green Card will need to complete at least two forms—an immigrant petition and a Green Card application. Someone else usually must file the petition for you (often referred to as sponsoring or petitioning for you), although you may be eligible to file for yourself in some cases. Here are the most common forms:
Form I-130, Petition for Alien Relative
Form I-140, Immigrant Petition for Alien Worker
Form I-730, Refugee/Asylee Relative Petition
Form I-589, Application for Asylum and for Withholding of Removal
Other petitions include:
Form I-360, Petition for Amerasian, Widow(er), or Special Immigrant
Form I-526, Immigrant Petition by Alien Entrepreneur
Form I-918, Petition of U Nonimmigrant Status
Form I-929, Petition for Qualifying Family Member of a U-1 Nonimmigrant

2. Are you inside or outside the United States?
If you are eligible to apply for a Green Card, you then need to determine which process to use – adjustment of status or consular processing.
Where are you?Application to UseNext Steps
Inside USAAdjustment of Status (USCIS)After approval of the petition, file Adjustment of Status
Outside USAConsular Processing (USDOS)