SET SERVEROUTPUT ON;
DECLARE 
  CURSOR bornRec IS 
     SELECT * FROM BORN
        WHERE DATREG between TO_DATE('23.08.1936','DD/MM/YYYY') AND TO_DATE('29.03.1955', 'DD/MM/YYYY');
  rec BORN%ROWTYPE; 
  KDR_FIRST_ID INTEGER;
BEGIN
  OPEN bornRec;
  LOOP    
    fetch bornRec into rec;
    exit when bornRec%NOTFOUND;
    SELECT KODRA_FIRST INTO KDR_FIRST_ID FROM ALL_AZ_AGS WHERE AZ_AGS_ID = rec.AZ_AGS_ID;   
    dbms_output.put_line(KDR_FIRST_ID);
  END LOOP;
  DBMS_OUTPUT.PUT_LINE('Progress END....');
END

Error starting at line : 4 in command -
DECLARE 
  CURSOR bornRec IS 
     SELECT * FROM BORN
        WHERE DATREG between TO_DATE('23.08.1936','DD/MM/YYYY') AND TO_DATE('29.03.1955', 'DD/MM/YYYY');
  rec BORN%ROWTYPE; 
  KDR_FIRST_ID INTEGER;
BEGIN
  OPEN bornRec;
  LOOP    
    fetch bornRec into rec;
    exit when bornRec%NOTFOUND;
    SELECT KODRA_FIRST INTO KDR_FIRST_ID FROM ALL_AZ_AGS WHERE AZ_AGS_ID = rec.AZ_AGS_ID;   
    dbms_output.put_line(KDR_FIRST_ID);
  END LOOP;
  DBMS_OUTPUT.PUT_LINE('Progress END....');
END;
Error report -
ORA-01403: no data found
ORA-06512: at line 12
01403. 00000 -  "no data found"
*Cause:    
*Action:
51454
51454
51454
50098
50098
........

SET SERVEROUTPUT ON;
DECLARE 
  CURSOR bornRec IS 
     SELECT * FROM BORN
        WHERE DATREG between TO_DATE('23.08.1936','DD/MM/YYYY') AND TO_DATE('29.03.1955', 'DD/MM/YYYY') for update;
  KDR_FIRST_ID INTEGER;
  COUNT_REC NUMBER;
BEGIN 
  for rec IN bornRec LOOP
      SELECT count(*) INTO COUNT_REC FROM ALL_AZ_AGS WHERE AZ_AGS_ID = rec.AZ_AGS_ID;
      IF COUNT_REC > 0 THEN
         SELECT KODRA_FIRST INTO KDR_FIRST_ID FROM ALL_AZ_AGS WHERE AZ_AGS_ID = rec.AZ_AGS_ID;
         dbms_output.put_line(rec.AZ_AGS_ID || ', ' ||  KDR_FIRST_ID);
        IF KDR_FIRST_ID IS NOT NULL THEN
          UPDATE BORN SET KODRA = KDR_FIRST_ID where current of bornRec;
        END IF;
      END IF;    
  END LOOP;
  DBMS_OUTPUT.PUT_LINE('Progress END....');
END;