So if I put the line to write before the word "adaugat" it overwrites the word, I pressed something and dunno how to undo it

looks like you hit the Insert Key: https://support.microsoft.com/en-gb/office/text-disappears-as-i-type-aa70b771-4733-47a6-bb98-78130afd083c#:~:text=Overtype%20mode%20is%20turned%20on,was%20pressed%20on%20the%20keyboard.

Ok thanks @acoustic-hair-60678