If you want to pump and save it is really easy,
you just keep it is a continer (
you can buy them at a baby store, or
you can get special bags to keep it in) and put that is the refrigerator if you are going to use it in the next couple of days, or freeze it if you start getting too much in the fridge. If it was in the fridge I would take it out 20 minutes prior to a feeding, let it get room temperature and then put it is warm (not boiling) water so it got warm.