using oracle9i.... did you create a default "starter" when you first set up oracle? Usually I thought a default init.ora file is created for that database.
The init file holds location info for the db tablespace files etc.
Let's assume your db is called orcl
Before startting your db, ensure that you have your db described in /etc/oratab: (assuming default path and version 9.0.1)
In your shell, try:
SQL> connect / as sysdba
If it starts up, try:
select sysdate from dual;
to see if comes back with the date.
mysql is pretty good but if you want stored procedures and functions maybe you could try PostgreSQL7.3.2 (like Oracle). but mysql is planning to implement this support soon.