Tips for Breastfeeding full term NICU baby

So my son is in NICU part time to be treated with IV antibiotics for 2 days post birth. The antibiotics can damage his kidneys so he needs extra hydration and as well had low blood sugar problems so they wanted me to start supplementing formula every 2-3 hours to keep that from dropping. Tomorrow we go home and no more antibiotics. Tomorrow is postpartum day 3, any tips to help establish supply since I have to supplement which makes feeding on demand difficult? As well, my boobs feel dry. They want me to pump every couple hours to encourage milk production but I am still getting like 1-3 drops per breast, I feel like my boobs are empty and he isn’t actually eating, just sucking for fun.