It is permissible under certain circumstances but a bit tricky. Your best bet , may be to leave the U.S. now and apply for an F-1 visa from an overseas consulate. You may find the links below helpful: http://myattorneyusa.com/change-of-status-from-b-visitor-to-f1m1-student https://www.alllaw.com/articles/nolo/us-immigration/applying-for-student-visa-while-on-tourist.html https://www.uscis.gov/working-in-the-united-states/students-and-exchange-visitors/students-and-employment/changing-to-a-nonimmigrant-f-or-m-student-status

Yes, you can. But be ready to wait incredibly long time, up to 2 years.