How do I use oral birth control?

So I just got isibloom birth control, but I know nothing about birth control. It says if I start on day 1 to start on the pill corresponding to that day and keep taking it until no orange pills are left, but its also in a flow chart/calendar that starts on Sunday. If i start on a Tuesday, do i go back and take the orange pills from the days before I started, or do i just keep going with the calendar and start the green ones when I reach it?

I dont know side effects either so any help would be great.