How do immigrant children go through the admission procedures?

Take immigration to the United States as an example.

In the United States, there is a matching school district near every house. You can find the corresponding school district, school name and address by entering your home address online. Every school district has a corresponding report on student attendance and grade ranking every year. After parents find a school that their children can attend through the internet, they can contact the school to help their children go through the admission procedures.