I believe what you need to get best access to your Oracle Database is installing Oracle SQL Developer. Free, can be installed in most any platform and grants you access to all you may want in an Oracle DB. You will need to install the latest Java 8 JDK first, since it runs on that.
I use it constantly to carry out queries and such on our corporate Oracle Database 12c we run on an Oracle Solaris 11 server. I'm using the same MBP as you, but with 10.11.2 El Capitan, with no issues.
Edit: just reread your message. If you already have access to an installed Oracle Database running elsewhere, SQL Developer will let you interact as needed. If you do NOT have a preexisting Oracle Database and need to install one, use VirtualBox to set up a virtual machine with adequate resources. Can be Windows (will require licensing) or Oracle Solaris (free). Once the VM is running, download the appropriate version of Oracle Database and install. You will need to know how to sysadmin the system on the VM, as well as handing the DB.