I've spent several nights in a tent with my ~65 lbs Golden, and I recommend getting as large a tent as is reasonable. For just me and her I used a 3 person tent, and I wouldn't want it any smaller than that.
I took her water bowl and put it on a waterproof tarp so if it spilled it wouldn't make too much of a mess, and put down a blanket for her to sleep on. Aside from that, take your pup out to the bathroom before hand, as it can be tough when you're nice and cozy in the sleeping bag.
Best of luck and congratulations!