Pumping and going back to work

Annica
My baby is 3 weeks old and I'm going back to work in about 3 weeks I'm EB and I'm just confused on how or when to start pumping for when I go back to work? Should I start now and introduce the bottle to my baby now? Or pump now stock up and introduce bottle a week beforehand? Also do I pump before or after feedings? How do I know I will be able to produce enough milk to save up? Sorry for so many questions. Share how you did it?