Go to the room that you want to be the spawn, click Room info then look the Room link:
You must be registered for see links
The 3 asterisks serves as the room ID, which can be replaced by the ID of the room. Now, let's do the spawning part for current users.
Simply run this query: UPDATE users SET `home_room` = '***'
As I said, the 3 asterisks serves as the room ID. Now, all current users are manage to be spawned on the room you have set. However, new users by default will be still be seeing the hotel view.
You can change the default room ID when a new user registered,
On NaviCat, right-click the table users... and a similar interface should appear as shown below:
Now, click home_room, as you can see it is selected as an arrow points out home_room. On the field where I wrote ROOMID, put your room id then click save. That should now make the spawn room.