Simply begin where you most think you should. Detoxing is actually very complex...you will be very surprised at how you'll feel at many stages.
Remember, too, that after you feel physically improved, you may need to deal with emotional/habitual issues which can be confusing.
If you do need to find clarity on these kinds of issues, simply relax and ask your inner self. Your body will lead you to the answers. Quite suddenly you will notice answers you didn't notice were there all along.
Be kind to yourself...you have come this far, to detoxing, on your own. Good for you.