Tent camping with 3 kids under 8 - what are we in for?

We're attempting our first real camping trip in 3 weeks. Got a Coleman 6-person tent, sleeping bags, the works. Our kids are 3, 5, and 7. I keep hearing horror stories about middle-of-the-night wake-ups and arguments over bathroom trips. Should we do a backyard test run first, or just rip the band-aid off? Any gear recommendations that actually made a difference for you guys? We're doing a state park about 45 min from home.