Starting birth control

Lexy

I’m waiting on my period and I’ve just got my first pack of pills to start birth control

Do I just start in the red section for the period but or do I start in the green?? But I’m about to get my period but I have no clue because today’s Friday and if I start in the red I’ll only have 3 days of red pills then I’ll be on green or do I just start the Friday before the green pills?