Can I schedule past appointments (for certification tracking purposes)?

Yes, you would do this just like you would schedule future appointments. Click on the CALENDAR TAB, then click on "New Appointment" button. You can click on the tiny calendar icon next to the date. To select past months/years, you'll see small arrows to the left of "the year". Click on this and it will display the previous year(s). You then click on the name of the corresponding month and on the date of the past appointments.