create package p is
procedure p(...) is
begin
<<here I'd like to dump all the arguments passed to my procedure without knowing what "..." is>>
end p;
end p;

SQL> CREATE OR REPLACE PROCEDURE P(A NUMBER,
  2                                B NUMBER,
  3                                C NUMBER,
  4                                D NUMBER,
  5                                E NUMBER) AS
  6  BEGIN
  7     NULL;
  8  END;
  9  /
 
Procedure created
 
SQL> sho err
No errors for PROCEDURE P 

SQL> select OBJECT_NAME, ARGUMENT_NAME, POSITION, SEQUENCE from USER_ARGUMENTS;
 
OBJECT_NAME                    ARGUMENT_NAME                    POSITION   SEQUENCE
------------------------------ ------------------------------ ---------- ----------
P                              E                                       5          5
P                              D                                       4          4
P                              C                                       3          3
P                              B                                       2          2
P                              A                                       1          1

SQL> CREATE OR REPLACE PROCEDURE P(A NUMBER,
  2                                B NUMBER,
  3                                C NUMBER,
  4                                D NUMBER,
  5                                E NUMBER) AS
  6  BEGIN
  7    for rec in (
  8     select ARGUMENT_NAME, POSITION from USER_ARGUMENTS 
  9     where OBJECT_NAME = 'P' order by POSITION
 10    ) loop
 11     dbms_output.put_line('Argument '||rec.position||' is named '||rec.argument_name);
 12     dbms_output.put_line('How to display value of argument '||reC.position||' there without having its name?');
 13    end loop;
 14  END;
 15  /

Procedure created.

SQL> exec p(1,2,3,4,5)
Argument 1 is named A
How to display value of argument 1 there without having its name?
Argument 2 is named B
How to display value of argument 2 there without having its name?
Argument 3 is named C
How to display value of argument 3 there without having its name?
Argument 4 is named D
How to display value of argument 4 there without having its name?
Argument 5 is named E
How to display value of argument 5 there without having its name?

PL/SQL procedure successfully completed.