Will Carington, works for Noodle
In order to apply to a U.S. university as an international student, you will generally need to complete an application (which will likely include essays, letters of recommendation, high school records, etc.) and submit scores from standardized tests such as the SAT, ACT, or TOEFL (for non-native English speakers).
Most schools, such as MIT, provide instructions for international applicants on their website; you can find MIT's instructions for international student admissions here.
Once you've been accepted to a U.S. university, you can then begin the process of applying for a U.S. student visa. NYU provides this helpful overview of the visa application process for admitted students on their international admissions page. More information about student visas is also available on the U.S. State Department's website.
To learn more, make sure to check out Noodle's resources for international students. One article that you might find helpful is "Tips for International Students Applying to U.S. Universities."
Hope this helps, and best of luck!