When I make new flashcards and choose a deck, instead of going in the right deck, another deck is created with the name “padrão” and this flashcard go with it.
Your note type has a Deck Override that is causing the cards to be created in that deck – and the deck to be created because it doesn’t exist. If it’s this, you’ll be able to fix it for this note type in the template editor (see the link).
Something is going wrong in the add-note process, causing the cards to be created in the “Default” deck – which if your original install language was Portuguese, might be named “Padrão”? For this, I would run Tools > Check Database and see if that clears it up.