Golly, when I were but a lad the only way to learn 3D software was to sit in front of easel for hours on end, learning depth perception by painting naked form after naked form.

I used to use one called Milkshape3D, I even bought it. I vaguely remember there was some controversy about it after a certain version though, like it was doing something dodgy to your computer if it detected that it wasn't registered or something.

I remember being obsessed with being able to 3D model as a preteen and devoured dozens of tutorials for Maya and 3dsmax but they were so complex that I never actually build anything myself until I used a much simpler program named MilkShape where you drag vertices into position manually. And now over 20 years later I’ve made more textured 3D models in picoCAD, the ultimate simple software, in a month than I did in a couple years of the above tools.

or suffer with Povray

since we're talking about old 3D software, Cyber Studio CAD-3D on Atari ST was also interesting: https://doudoroff.com/atari/cad3d.html