So I don’t know if you have worked night shift before but it is different for everyone. Some adjust and some don’t. I am one that doesn’t but still have to hold down a job. I drink coffee before going into work but only drink water during it. Coffee may keep me awake during the shift but generally just makes me feel jittery and awful and my IV skills seem to decline, so hence the reason for only the water during the shift itself.
As for sleep.....honestly, I am often awake the entire day before my first shift, sleep a few hours before the next shift, and then usually sleep a decent amount before the third shift because I am so tired.
I generally adjust back to days on my days off which generally makes me constantly exhausted, but I have other priorities and can’t stay on a night schedule constantly. Eating healthy is so important though! I generally eat soup, fruit, and tons of water during a shift. Hope this helps....