Best way to use insert statement on Oracle
insert first
when CPF is null 
then into COMPANIES_ADDRESS (ZIPCODE, STREET, "NUMBER")
else into CUSTOMERS_ADDRESS (ZIPCODE, STREET, "NUMBER")
select  V_ZIPCOD, V_STREET, V_NUMBER 
from    dual


P.s.
Using reserved word as identifiers (in this case NUMBER as a column name) is a really bad practice.