You get access to all 2D and 3D design features, allowing you to fully test the software on your system.
The best option, but strictly for students and educators.
Here is the deep review of your options, the legality, the user experience, and the alternatives.
Here is why:
However, if you just need to view or edit a DWG file quickly, try (formerly AutoCAD 360). It runs in your browser (Chrome/Safari). The free tier is very limited, but it allows basic viewing, redlining, and light editing without installing anything on your Mac.