Like everyone else said, it'll take you a few landings to really get the idea of judging your height and such. To restate important stuff, definitely get some experience with no lights. It'll happen eventually.
But to kinda add, and touch on what max briefly mentioned, study up on runway illusions. Night flying can really screw with you. Fly the same approach as you would during the daytime. If you have a VASI/PAPI, use it to your advantage...but don't fully rely on it because not all airports will have one.
Look through medical factors...such as autokinesis and how to scan for aircraft.
When you do your night cross countries, you'll realize your using your instruments, charts and VOR's (etc) much more because your landmarks/checkpoints will be different. Keep in mind you can't see as many objects as you can during the day. Towns can sometimes be good, if you live in the middle of no where. Following roads is nice if your not in a major city (we have I-81)...use good judgement when picking out your landmarks.
Take another glance at airport beacons and what their colors mean. Before you go to an unfamiliar field, glance again at the airport diagrams. Things look much different at night, and you'll find yourself utterly lost if you don't have an idea of what to expect.
Like someone mentioned, keep an eye out for clouds. They are much harder to spot at night. If you start seeing lights on the ground disappear, take action...your wingtip strobes will become nice and blinding if you start entering clouds too. Make sure to get a nice thorough weather briefing, and fly a bit higher if need be...especially if around terrain that isn't so emergency friendly. Try to have emergency landing locations in mind prior to departing. Know the terrain...if there's going to be lotsa mountains on your left, and open fields to your right...have a pre-emergency plan.
There's probably more I could add. I know I strayed into night cross country stuff, but you'll eventually need it anyway.
Have a blast with your night flying, and let us know how it all turns out. It's an absolute blast.
Jenn