Steps to use oracle10g:

1.Install oracle10g/11g
2.Click on windows start symbol  type 'sql'
-----then select "Run SQL Command Line"
3.then type 'conn'
4.enter username and pasword which u set at installation time.eg unm='system'  psw='system'.
5.u cannot create database here 
//u r already in mysql db
6. now create tables
7.quit




//Oracle 10g is Oracle's grid computing product group including (among other things) a database management system (DBMS) and an application server.



thank you.......................