EaselPro is great introductory software, and you can just use it indefinitely if you only want to make 2D designs (signs, etc.). But if you want to do actual 3D carving (well, relief carving with curves), you’ll need different software.
I think VCarve, or another one in the Vectric suite, is the more accessible (in terms of learning curve) software that lets you really unlock the functionality of CNC/the XCarve. However, it is expensive.
There is just-as-functional software available for free (for noncommercial and low-volume commercial work)… Autodesk’s Fusion360. However, it has a somewhat higher learning curve to get started. If you have the money, VCarve is good. If you have time to commit to learning Fusion360, it is arguably better… maybe… I dunno. I think it’s apples and oranges.
Be aware that (unless they’ve changed this) vCarve’s free trial won’t let you save or export your own designs. You will have full access to all of the design tools, so you can familiarize yourself with the software, but won’t be able to save your work or send it to your machine. When they say you can carve designs on your CNC, they mean a handful of ready-made sample designs that you download from their site.
Also, as Haldor has brought up, you’ll need a gcode sender if you move away from Easel. UGS (Universal G-code Sender) is good, and it’s free. There are others, but I know UGS.