Studio and Community Edition are not meant to work together.
DataStax Studio is meant for use with DataStax Enterprise (in particular, for use exploring graph data in DSE). The Community edition you have installed only contains a distribution of Apache Cassandra (+ OpsCenter) and not DataStax Enterprise. So if you want to use DataStax Studio, you're going to have to get a copy of DataStax Enterprise first.
Since you're on Windows (and not on Windows 10), your options are a little limited. DSE doesn't run on Windows natively, so you'll have to use a Virtual Machine of some kind. There is a Sandbox image available from the DataStax Academy downloads page for both VirtualBox or VMWare, or you can always create your own VM (running Ubuntu or the Linux flavor of your choice) and Install DSE yourself.
Good luck!