I’ve hiked half dome three times. My favorite was a full moon hike where we left lower pines around 9pm. Needed a head lamp for the first couple of hours but then it was bright enough without one the rest of the trip. It was by far my favorite for several reasons: no crowds going up the cables, cool weather, amazing sunrise.

For any type of half dome attempt you need to train.  Focus more on endurance and less on speed. It’s a long day with steep ascent. Depending on your skill and fitness level you could be out there 12+ hours. What people don’t realize is that going downhill is incredibly straining as well.  It helps to incorporate both climbing up and down motions in your workouts. If you can get out hiking with elevation gain that is ideal. During the week get on a stair climber. Try to build up to 30 mins, then 45, then an hour. 

Bring plenty of water, snacks, and grippy gloves for the cables, sunscreen.  If they still allow the night ascent you will want to pack warm clothes or even a light sleeping bag for the summit. It can get pretty cold while waiting for the sunrise.

secure a permit. I’m not sure if one is required now for a night hike so I would check on that.