Yes, if you have some SQL (the language, not SQL Server) knowledge it will surely help you.
The first thing I would recommend would be to download the express edition of Oracle Database 10g, which is completely free. Then you can start learning from the documentation library which includes interesting courses such as “2 day DBA” and “2 day Developer Guide”, among others.
It is better that, if you have to do oracle certification i.e. OCP…. It has two parts one for Application Developer and other is Database Administrator (DBA). This is absolutely a global cert and you may get good jobs also. Other than there r so many certification in the same field like SQL Server or MySQL Server and so on. But must do a global certification. Rest just googling and you get all of the details!