How to use local variables in stored procedures?

Oracle style variables:

DECLARE v_MyVariable1 NUMBER;
DECLARE v_MyVariable2 VARCHAR2(100);

BEGIN
    v_MyVariable1 := 0;
    SELECT INTO v_MyVariable2 CUSTOMER_NAME
        FROM CUSTOMERS;

    SELECT INTO v_MyVariable1 CUSTOMER_HISTORY_SEQ.NEXTVAL FROM DUAL;

    INSERT INTO CUSTOMERS_HISTORY (CUSTOMER_ID, CUSTOMER_NAME) VALUES (v_MyVariable1, v_MyVariable2);

    EXCEPTION
        WHEN OTHERS THEN
            NULL;
END;