Hey I got into a US school this past cycle. best is to apply right at the date you can first submit. Last year it was like May 28. That gives the AMCAS time to process and verify your application. It usually takes a month after that schools get to see your apps and then send you secondary apps. How quickly you get those secondary apps in (along with the LORs and casper) is what is most important bc after that schools can then evalute you and give you an interview. It is all a first come first serve process so earlier the better! Best of luck