You will need to add a a room type before you are able to add rooms in Preno.
Room Types in Preno allow you to group similar rooms together, such as One Bedroom, Two Bedroom or Suite.
Add a Room Type
To add a Room Type
Go to Settings > Rooms > Room types & rooms
Click + Add room type
Enter the details
Room type name
Rate name
Base rate
Extra guest rate (put 0 if not applicable)
Included in occupancy (guests included in the nightly rate)
Tick 'Exclude from occupancy' if you want the room type excluded from your reports.
Click Add room type
The Room Type you’ve added will then be displayed in the list in Settings. Once a room is assigned to the Room Type it will show on the Grid.
Your new Room Type will initially be unmapped to your Channel Manager so it can't be booked online.
If you want to keep a room type intentionally offline, avoid linking it to your direct booking engine. This is particularly useful for event-specific room types or those being prepared for future availability.
If you’d like to map this room to your Channel Manager; you apply apply the guidance from step 2 onwards in the below article
https://help.prenohq.com/en/articles/11429663-booking-engine-add-rate-plan-multiple-rate-plans