If you are just starting out in CNC. I would suggest using Carbide Create or Easel. They are both free and pretty easy to use to get you feet wet.
Once you’ve got the hang of things upgrade to something like VCarve Desktop/PRO or Carvco Maker.
Fusion 360 also free and more powerful but there is a steep learning curve unless you are already comfortable with CAD/CAM software.
There are quite a few posts on this subject. If you type “software” in the search you’ll get a bunch of hits. Here are a couple of threads…