I stopped after a few classes but I was amazed at how good I got in a short amount of time after learning how to break stuff down which isn't something I really thought about before. By all metrics I'm still a pretty terrible drawer but prior to that stick figures would have been challenging.

Another good resource for learning how to draw realistically is the book: "Drawing on the Right Side of the Brain". The premise is that your brain wants to take shortcuts and group/chunk things together on what they should look like, instead of what things actually look like. But even a rectangle in real life has non-right-angles because of perspective, etc.. And if you draw what you actually see, then the drawings come out correct. Some of the exercises are copying other drawings placed upside-down, so that you brain doesn't try to over-interpret things. I can't recommend this enough if you want to go from a beginner to something respectable in drawing abilities.

https://www.amazon.com/Drawing-Right-Side-Brain-Definitive/d...

https://kk.org/cooltools/drawing-on-the-right-side-of-the-br...

Drawing from circles, squares, triangles, etc. in art is called "construction" and is definitely a foundational technique. It really is amazing how much easier drawing becomes once it's understood (and practiced).