First you're gonna have to set your standards a whole lot lower
Your priority needs are going to change every day--sometimes family, sometimes work, sometimes school and so being flexible is really important. Do what you have to do and at the end of the day as long as everyone's safe and nobody's hungry, you're good.
I'm guessing you want some concrete suggestions, though and I'm happy to share what works in my large family with two working parents.
Buy lots of basics for your kids; I really stocked up on underclothes and blue jeans and lots of cheap shirts/sweatshirts. A lot of things can be worn by both boys and girls (well, maybe not the underwear) and that helps.
Paper plates, Costco dinners (you know the big packs of frozen stuff you just have to throw in the oven), a willingness to let visitors in even though they have to shove laundry (hopefully clean) off the couch in order to sit down.
Plan ahead enough so that you're not having to stop at the gas station at 0515 in the morning on your way to clinical in the middle of a freezing night, but otherwise don't sweat the day to day stuff. Nursing school is notorious for changing their (and therefore your) schedule on very short notice.
I take my schoolbooks/notecards/study guides with me everywhere. I get a lot of studying done waiting at the grocery store, preschool, etc.
Most importantly, take time for yourself. It's more than worth the time it takes. Read, run, hike :wink2: , but do something that has NOTHING to do with school. School only lasts a few years, but your sanity has to see you through to the end.
Good luck. You can do it!