The CNC router comes with a DSP (digital system processor) pendant-type controller which runs off a USB to actually provide the motion control -although other controllers are available, some even run direct from a Windows PC via serial connection - but we think the DSP is more reliable from experience. The DSP requires instructions to do anything useful and needs a software package that can take designs and change them into bunch of numbers which the machine can understand when it moves around machining a job. The bit that does this is called a "POST PROCESSOR" within the CAD/CAM (computer aided design/Computer aided manufacture) you'll need.
For design and creating your artwork (CAD) and that important "post processing/toolpathing" (CAM) depends what you want to do, might require different software for each type of work & it is important to understand what machining methods you will need in order to produce your work.
When it comes to software there is a significant difference in both features and price on the multiple software titles out there & depending on what type of work you are doing, you may be able to get a simple cheaper package that will do everything you need.
E.g If you plan on making wooden Signs or 2D parts Vectric's VCarve Pro is as good a program with heaps of features but there's also a cheaper option in the form of Cut 2D Pro from the same website.
If 3D (2.5D) is what you are looking to do- VCarve Pro is also a good choice although it's not a true CNC machining package like Autodesk HSM for instance, but it'll still be great for most jobs on your CNC router.
Other sofwtare packages work as well -and there are heaps available- though MakerspaceNZ will be less able to assist with developing a workflow that works for you.
If you already use CAD software for developing your stuff... e.g. AutoCAD or Illustrator, Sketchup etc, all your drawings can be imported into VCarve packages as a dxfs. This makes it simple if you're already using CAD drawings & will keep you from having to redo all the work you already have invested time into. Then it's only a matter of importing these drawings into your CAD/CAM software to produce the G-code (postprocessed or toolpath code) and run your job.