When you arrive in the United States on your K-1 visa, you then have 90 days until the visa expires. In that 90 days, you must:
Get married
Acquire your official marriage certificate
Prepare your paperwork for adjustment of status
The following forms are needed for an adjustment of status from a K-1 visa to a green card:
Form I-485, Application to Register Permanent Residence or Adjust Status
Form I-864, Affidavit of Support
Form I-693, Report of Medical Examination and Vaccination
Form I-131, Application for Travel Document
In addition to these forms, you may also apply for your work permit using Form I-765, Application for Employment Authorization.