What is a
local student?

F-1 visas may be valid for entry to the United States for up to 10 years, but F-1 status (the ability to legally remain in the United States while enrolled in a full course of study) typically lasts for the duration of the student’s approved course.
F-1 visa students must return to their home country within 60 days of the completion of their program.

– Attend a SEVP-approved language training program or academic institution.
– Maintain full-time status.
– Demonstrate financial ability to pay for their cost of living and studying in the United States. You, or your sponsor, must provide your school with a bank statement or a certified bank letter proving that you (or your sponsor) possess sufficient available funds to cover the total cost of attendance of your program.
– Maintain foreign residence and demonstrate intent to return upon course completion.

The I-20 form is not the F-1 (student) visa itself. However, you will need to get an I-20 before you can qualify for the F-1 visa.
The I-20 form is a United States Department of Homeland Security document and can only be issued by a qualified school official (DSO or PDSO) at an institution that is authorized under Federal Law to enroll non-immigrant students.
The I-20 is a “Certificate of Eligibility for Non-immigrant Student Status.”

It depends on the country (and sometimes the city) where you will be applying for your visa. Each United States embassy and consulate has different processing times, which typically range from a few days to a few weeks.
You can visit the website of the U.S. embassy or consulate where you will be applying to see their current wait times.