Are you currently staying in the United States? To obtain a Green Card as a family preference immigrant, the following are the requirements:
Form I-485, Application to Register Permanent Residence or Adjust Status is to be filed.
An Inspection will be conducted. Then you are admitted or paroled into the USA.
If you are physically present in the USA at the time of applying in From I-485, you may receive an immigration Visa.
An immigrant visa will be given to you at the time you file your Form I-485 and till the time USCIS makes a final decision on your application
Generally, to be eligible to adjust status, you should be present in the United States after the inspection, by an immigration officer.
Eligibility criteria for getting an Immigrant Visa
An approved Form I-130 filed on your behalf or
A pending Form I-130 or
A Form I-130 filed together with your Form I-485.