You can apply for your visa as soon as you receive your I-20, but no earlier than 120 days before your studies begin. This date is listed under Start on Studies on your I-20.
If you already have an I-20 and are sent a new one from your university because for example you are postponing your college start, you can apply for the visa with your old I-20. Then use both I-20s when you leave.
No, you must visit a U.S. consulate in the country where you live. You cannot make an appointment for a visa in another country if you are not a citizen of that country.
Before you can schedule a visa appointment, you will have to pay the visa fee. You can do this by clicking on the button on the top left of your online consular account that says Schedule Appointment. Then you will need to answer all of the ...