About sending test scores-
Send official SAT scores to USC through College Board.
https://ecl.collegeboard.com/account...2Fmyscores.jsp
It is not imperative that scores be received by USC by the deadline but should be there within a week or two of the deadline.
If you want to make sure that USC receives your scores close to the application deadline, you can send a copy of your scores to USC with form 5. You can print a copy of the online report. You will still need to make sure they will receive an official copy from College Board.
Admissions will not tell you if they have received your scores until after they receive your application.