@GregNickoloff I finally discovered a couple of good tutorials on YT on "Sketchup for woodworkers" and it clicked. I was trying to "just make it happen" and my brain wasn't registering on how to properly use it.

There are many really, really good tutorials... and many that are...well...on the other end of the spectrum. I'm not all that proficient with it, but good enough to figure out dimensions and so on.