I just went to hospital tour last night. Nurse said to pack (1) outfit for baby. Comfy nightgown for me if I don't want the gowns they have. Leaving outfit (no jeans), slippers, open toed shoes for when you leave because feet might be swollen and that's it. Hopefully your hospital supplies you with everything you need for baby and yourself while you're there.
Baby wont need much, they are in hospital clothes and blankets for the most time. Maybe just an outfit for going home and pictures. Bring a newborn and 0-3....you wont need much. No underwear, only going home clothes! Good luck!