Comment by TeMPOraL
Most of my issues seem to be about power - I have no feel for the relevant math, so even as I remember the basic equations and methods, I never feel certain I'm calculating it right. So in terms of hands-on experience, I pretty much jumped straight from burning through-hole resistors with 12V battery to ignite rocket motors made of PVC and caramel fuel, to Arduinos and RPIs and NodeMCUs -- basically, stuff that comes with an USB port it can draw power from...
Thanks for the links, I'll work through them and hopefully come out with some understanding at the end of this process :).
Note, part of the fun is the forensic analysis to figure out why stuff didn't work the first time... Maybe a LDO Voron 3d printer kit would be a fun project too =3