In order to change a room name you just need to go to Room Manager, double click the room for which you want to change the name to open it, then enter the desired name here:
Note that the rooms in Bed View are in alphabetical order.
If your rooms have their own names and there are not in alphabetical order in real life, you can add a number before the name in the system to have them in the order you need. For example:
The rooms on Bed View will be in the order you see them in Room Manager.