I used to work that shift in a hospital. Basically, you were told correct. There are a few things I can think of to warn you about. Finish everything you need to finish as quick as possible, because while there is a lot of downtime, it will get busy quick. A lot of transfers from different units happen at this time, because it's easier to do than during the day when the halls are busier. At least that's how it was where I worked.
The vital signs depend on what type of unit you work on. Some units the nurses prefer to take them because the patients need to be closely monitored and they're already on a tele monitoring anyway. In other units, they will have you do every vital sign and this can get tough if there are a bunch of abnormal ones and you have to hunt down every nurse to let them know it. If you have this type of assignment, I would strongly suggest writing down the nurses' names for each patient so you don't have to keep looking at the board or roster. Good luck! It should be pretty easy once you get used to it <3