you have to wait till the schools invite you to complete their secondaries. Some schools send their secondaries to every applicant while some schools only select a few hundred or a certain percentage of the applicants to complete their secondaries.
However, you can have the secondary filled out now and when you receive one from that school, then you're one step ahead of the process. You just can't send in the secondary until they send you one though. Also, i think most of the secondaries on the school's websites are from last years and may not be the same this year. I heard that Duke didn't have the same secondary questions from the previous year; but a lot of schools use the same one. You might just have to transfer in your answers on the secondaries they send you.
good luck.
