I'm not overly fond of using open source or 'free' CAM software. I much prefer something professional grade that has support. When the post processor is going screwy, and there's a looming deadline, it's good to have someone you can count on to assist with technical problems. Trying to avail yourself to some forum with people that have no motivation to help you and no reason to be 'timely' in their answers is not what I would call proper risk management.
The 'free' and 'open source' software also typically has a steep learning curve as most of it is more 'raw' and unhelpful, nor do they often have an intuitive UI/GUI to make things easy to get to. They seem to be typically designed for use by people who already know the answers and just need a box to plug the answer into. There are exceptions of course.
If you're just playing around at home, there are more 'professional' packages for free, or near to it. I believe Autodesk is still offering their Fusion360 software for free to hobbyists/small-business. I have used it for modeling and 3d printing but not for programming mills/lathes. I've heard good things about the CAM programming side of things from people who would know about these things.
If you're new - don't make it any harder than it has to be. Get something made by professionals - not hobbyists.