Help I'm so lost!

I have 1 week old twins and was just wondering how often and how much breastmilk any of you ladies fed your babies, my maternal nurse came out today and had me in tears because I couldn't get them to latch and I have been pumping and then giving that to them, but I have had that many different opinions on when I should be feeding them, some say 2 hrs, 3hrs, 4hrs, any advice would be appreciated xx