Before a person's name, you say 'Mr' for a man.
Senhor Ferreira = Mr Smith (pronounced 'Mister')
For a woman, traditionally we used 'Mrs' if she was married and 'Miss' if she was unmarried. Nowadays, it is becoming more common to use 'Ms', which doesn't tell you about the woman's marital status.
Senhora Ferreira = Miss Smith
Mrs Smith
Ms Smith
Miss ---> pronounced 'Miss'
Mrs ---> pronounced 'Missiz'
Ms ---> pronounced 'Miz' or 'Muz'
If you are not using the person's name, then 'Senhor' and 'Senhora' are translated as 'sir' or 'madam'. For example:
Thank you, sir.
Come this way, madam.