Before getting Perl involved you'll need to ensure you can connect from your Linux system to Oracle running elsewhere. Ensure that tnsnames.ora is configured correctly then try to connect using Oracle tools such as sqlplus/tnsping. Consult the Oracle documentation for help on this. Once this works you should be able to use Perl (DBI with DBD::Oracle) to connect to Oracle.

Update: Come to think of it, the oracle client tools provide a Java GUI based Wizard app for configuring and testing connections. Perhaps this is useful to you.