I have immigrant visa and I paid $165 on July 27 but I did not get my green card how long I have to wait to have it. Am in big trouble because I could not work please I need your help?

When you entered the United States with your immigrant visa, the immigrant visa was endorsed, and immediately became a temporary I-551 (green card) for one year. That endorsed visa stamp is equivalent to a physical green card in every way, and can be used to work and/or travel as a permanent resident.

If you entered US with immigrant visa, all you need to do is call USCIS and notify them that you are already in US. You should receive your GC in approx 3 weeks.