I have used CamBam for a number of years. It works very well for 2D and 2.5D operations. I believe it will do full 3D but I have never done it. I still use it for quick jobs, just last evening in fact.
For anything complex, I use Fusion 360, full featured professional solid modeling and CAM functionality, and the best part is that it is FREE to hobbyists and startups. A bit of a learning curve, but there is a huge base of user groups and online tutorials. This is one of the best
https://academy.titansofcnc.com/ it's free and starts you at zero and takes you from simple to complex parts in simple exercises. I was making parts in a couple of days using this course.