New line in Oracle PL/SQL

Use CHR(13) || CHR(10)

DECLARE 
   NEW_LINE_   CONSTANT VARCHAR2(2)  := CHR(13) || CHR(10);
BEGIN
   Dbms_Output.Put_Line('Hi, '    || NEW_LINE_ || 
                        'good'    || NEW_LINE_ ||
                        'morning' || NEW_LINE_ ||
                        'friends');
END;

Output