Pumping questions?!

Erbear
So I'm breastfeeding, my babe is a week and half old and I want to start pumping to supplement and save up but I'm so confused... Do I pump after I feed, what's the best amounts to save at a time? I need some feedback on how you ladies pump and breastfeed and what's worked and doesn't for you. If anyone had a sample of their trout one I'd love to hear it! Thanks!