Hi @Mateus9 I hope that you don't mind a reply in English - my written portuguese is very rusty!
Yes, you need to create a listing for EACH room. That way you can book one room, and the other room is still available. When you have two separate listings, you can decide to manually "block" one if you wish to rent out both rooms to the same guest. I haven't looked at your listing, but that's how I think that you can do it.
So you can have 3 separate listings:
Room A
Room B
Rooms A + B together.
I hope that helps!