Honestly I don’t know what I don’t know.

Thats understandable, thats why I was saying that when you start using your printer the needs/areas to improve will become aparent and so what you need to learn about hardware will also become apparent.

I’d say printer recommendations, specifically how to pick one, where to buy from, should I build it myself?

This depends on where you are located (US, EU, Asia etc) and what type of printer you are interested in. Judging from the projects you have in mind I guess you are looking into FFF/FDM and not any type of resin printer.

Generally what people will recommend depends on your budget and mindset. If you want a printer as a tool and not something you want to tinker/improve and learn in depth about itself then you might want to avoid building your own from scratch. If your budget is in the <300$/€ range then a partial kit may be unavoidable. In general here is what I think. Keep in mind I haven't bought a printer in a while (~3yrs) so I may be out of date.

• Voron Printers - 100% diy well performing and regarded machines. Chalenging as a first printer but they are well documented and have an active, helpfull community. Open Source. Here is where I would start [400 - 2000 $ machines depending on what you pick]

• [Creality Ender 3 (V2 or whatever flavour)] - Simple "kit" a few bolts really, well documented popular starter printer, performs fine, budget printer. When I bought mine I also bought a flasher to change the firmware to Marlin from the closed version they had, not sure if thats relevant anymore. I would buy from their store on aliexpress [200-250 $]

• Prusa - Well build, well supported from the manufacturer and community, quality parts and engineering. I would look at MK4/MK3 but you may want something like the mini. Available in kits and assembled. Open Source. Buy from their store. [~450€ for the mini and 700-1200 MK3/MK4 depending on kit vs assembled]

• Bamboo Lab X1 Carbon - The new and (very) shiny kid on the block. They seem to offer a very well build, very fast printer. They also seem to support and case so far. Closed Source. I don't know the best place to buy from. [1500€]

Above these price point you would be getting to more industrial/proffessional machines. Any cheaper than the ender and you will be in for a quite bit of tinkering (the ender may also have some qc issues). In between the 200-800 range is a bit tricky. The Prusa mini is a good choice but it is limited in size and has other drawbacks. There are some Creality models that were/are popular and work fine ( Creality CR10 ) but I have not paid much attention in the last few years to give you an educated answer. Personally if I was at the 400+ range I'd look into getting a Voron.