Unity Learn has instructions for installing ProBuilder. It has a few tutorials for learning to do more for people that are already familiar with it. But, the one set of lessons that Unity Learn had for learning to use ProBuilder, Building 3D Models with ProBuilder just returns a 404 error. The Asset Management with FBX Exporter, ProBuilder, and PolyBrush tutorial might be able to fill in for it, but that sound more like it’s about mixing multiple tools to get to the final product. Not to mention, wasn’t PolyBrush deprecated. Why is the most complete tutorial for ProBuilder relying on tools that Unity is throwing out, while the tutorial for simply learning ProBuilder is simply missing.
The entire reason I was looking for the Building 3D Models with ProBuilder is because I wanted to prototype something and I remember that was a pretty good tutorial for learning the basics of ProBuilder.