So far, no one has mentioned VCarve.
First, not free. They have a fairly wide range of products, and a pricing model that allows you buy in at the low end and step up to more sophisticated products as your skills increase. They’ll charge you for full point upgrades, so 10 to 10.5 was free, but they just came out with 11, which I’ll have to pay for if I want it.
VCarve is pretty much dedicated to the home CNC market, so you’ll find it easier to use than Fusion, which is kind of all things to all people.