I know that the US system is really different from our home countries.
This is a slide that I realized, I hope it will make it simplier for you to understand the steps.
If you have any question, feel free to let a comment below or to send an email here.
ONCE YOU SEND EVERYTHING TO MIRACOSTA, you will receive a package including your I-20. You are good to go for your interview at the embassy and get your visa!