I absolutely recommend FreeCad. It can be pretty hard to learn because it feels unfamiliar at first if you come from Inventor (Like me Back in the day). But it is FOSS and that alone is a big plus. Also it's pretty versatile, you can notl only do 3d CAD, but also architecture, structural Analysis (FEA), or CAM if you are into that sort of thing. Give it a try, and dont be discouraged by the steep learning curve!