The basic daytime ticket for the entire complex is called "Alhambra General". Folks who want to double up and also go at night seem to focus on the Nasrid Palaces (the most beautiful part of the Alhambra). That would be the "Night Visit to Nasrid Palaces" ticket. You can spend well over half a day at the Alhambra, and I don't think the nighttime hours allow for that long a visit, so I would skip the "Night Visit to Gardens and Generalife" ticket; you will see those areas on your daytime visit.
I encourage you to stop at the visitor center at the beginning of your daytime to visit to find out what is closed that day and what parts of the complex may have limited hours. It's not the same every day, and there might be something you especially want to see and could miss if you didn't make a point of checking. Aside from the Nasrid Palaces, the prime target for which you'll have a specified entry time, I'd want to see the Charles V Palace, which is a museum showing some of the most beautiful architectural bits and pieces that have been taken indoors as protection from the elements.
I liked the audio guide. You won't need it while you're with your guide, of course, but you might want to use it on your nighttime visit.
Keep in mind that a few parts of the Alhambra (most definitely including the Nasrid Palaces) can be entered only one time on a single ticket. Therefore, if your guide takes you through the Nasrid Palaces first, and then on to other parts of the Alhambra, you will not be able to return to the Nasrid Palaces later that day. Therefore, I'd encourage you to think about what that means if either of you are into photography. Conditions will be crowded in the palaces, and it takes time if you want to take photos without a lot of random people in them. Based on my 2019 experience, it will not be less crowded at night.
