If you already have a guitar and it does not have any USB connections, then you will need a DI (Direct Interface) box. You can get all kinds, I really couldn't advise you. If you are planning on recording get a proper mixer with USB, you'll thank yourself!

I have a mfx pedal with USB connection that I have used. That worked fine, plus I had the effects and amps and could even run a mic record with it plus use it standalone with an amp.