How to incorporate pumping into breastfeeding schedule?

I have a 3 week old and was told to wait until she was 4 weeks to start using my pump but I have no idea how often or for how long I’m supposed to use my pump?

I still plan on breastfeeding, it’s just that sometimes I’d like my husband to feed her so i can get a longer stretch of sleep!

She feeds every 2-3 hours and for about 15-20 minutes on one side!