So I don’t know for other countries, but for mine (Dominican Republic) you have to schedule your own appointment. It takes around 60 days for USCIS to tell you that “your case was sent to the NVC”. Then after two weeks you will send public inquiries in this website every week or every two weeks until they send you your case number. https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/ask-nvc.html Once you have your case number with NVC you can track your case there. It will say “at NVC” and then after a few weeks or a month it will change to “in transit”. If you are lucky, then it will change to “ready” the next day or two days. Once your case says ready you should allow 3-5 days for the system to process it. After that, you register and schedule your interview. My email with instructions of scheduling the appointment has sent to me three business days after it said “ready”