Hello @Dragica21
You would need to create a different listing per room so that they each have their own calendar and pricing.
Here is a link on how to do this:
https://www.airbnb.co.uk/help/article/289
You could also have another listing for someone who wants to rent out the whole house with all the 3 bedrooms. This would be your parent listing and the individual bedrooms would be the child listings.
What this means is that if someone rents out the whole house, the calendars for the individual rooms would be blocked. You need to look up how to synchronise calendars on Airbnb.
Hope this helps!
Joëlle