Immigration, Customs and Boarding for International Travel to USA
Stand in the line for Immigration Check. Proceed when they call you. In some countries, this is handled by police officers. Proceed immediately when they call you and keep your handbag above/near your seat. They will check your passport and ask questions about your journey and purpose. After this, ask at the counter where to go next.

Next go to the Customs Check. They will ask you if you have anything to declare. Normally, you won't have anything to declare, just clothes and personal belongings. Then ask at the counter where to go next. Many times, immigration and customs counter is the same where the formalities are done together.

Proceed toward the gate number they gave you at check-in. The gate number is also on the boarding Pass. All gates are on the lower level.

You might end up with time on your hands. There are places to sit and shops to browse.

Next, go to the Security Check. Here they will scan every person (gents and ladies separate) and X-ray hand baggage. Next you will wait in the hall for the boarding announcement.

Normally they seat people in the following order: handicapped, first class, business class, last rows, middle rows, and front rows. Keep your boarding pass ready and enter the plane. Flight attendant may help you locate your seat; if not, ask them. Put your hand-baggage in an overhead compartment (or under your seat). There will be blankets on each seat. If they are not there, ask the flight attendant for one.