I must mention that "32 characters" is only my guess.
In the Handbook it is said: "The root user's password should be long (12 characters or more) and impossible to guess."
Also, i must again say that in my case we speak just about a humble home desktop, without a ""ssh" access"" or whatever complicated.
Thank you for your answers and tips. I will make a very strong password for root and a strong one for a user in the sudo group.