Day 2 and no breast milk

I experienced the same when have my first child. I almost want to give up breastfeeding. Experience telling me, drink more water and sleep more. deep sleep 2 hours is considered good already. don't don't stress yourself. coz too stressful cannot sleep well. if milk come/engorge pump it and let baby suck it. Now i have my 2nd child (3 months old) , milk flow is good.