I will just give you a paragraph of the necessary things.
You will need a tripod and a cable or remote release.
The basic understanding of your camera functions, mainly working in “Manual” mode.
Also knowing how to turn off your auto focus is a huge issue. Please shut off your “Long exposure noise reduction’ as it isn’t needed and will slow the group down.
A small flashlight or headlamp of some sort which makes it easier to adjust your camera in the dark.
A small stool as we will be working with 2 rows and the back row will be standing and shooting over the front row which will be on stools.
Most importantly dress for the weather, remember you will be standing or sitting still for quite awhile and it will seem to be colder than it really is.
We usually recommend a shorter than normal lens. Say in the 24mm range. Ideally a zoom as everyone prefers a different viewpoint. We normally advise and shoot with ourselves with a 24. We will be covering quite a field of view as the night progresses.
Sunset by then will be before 5pm. We can start anytime really. I will check with Chris and make sure he can be ready to go to be there for 730.
Hope this helps,