What's the best way to go about this? I've never coded using two languages before, let alone for an android phone
Using the Android NDK you can build a native library in C/C++ and by exporting the functions as native you can call your functions as if it was standard Java code once you've initialised the library. There's plenty of tutorials available on getting started with the NDK as well as samples provided by Google.
It's important to note that the NDK isn't necessary for a lot of purposes, see the FAQ:
As for developing on an Android device, I would suggest downloading the SDK (and NDK if your application requires), getting the emulator working, and having a go at the tutorials, reading the technical articles for best practices, and making sure you understand the application fundamentals.