Safety considerations (for parts) for a beginner building with expensive parts
I'm looking for guidelines like "don't connect a pin of type A to a pin of type B without a gate of type G in between", or "be sure to add resistors/caps here and here", or "power up this pin/chip before this other pin/chip" or "use a such-and-such circuit to condition the power" ...


These "tips" are instructions given in the data sheet and developer's manual.

Engineering (usually) isn't "add a resistor here and there"; it's about reason-based design.

Now, this sounds like something that used to power PDP-11 computers? Don't know whether official documentation is available, but I'm sure there's retrocomputing communities with their own documentation and reference designs.

I'd actually recommend starting with designing a circuit board for a more modern microcontroller. You'll learn a lot of the skills that are useful for doing it right the first time with your expensive one, cheaply, and without being as prone to die due to beginner's mistakes.

Start easy, work towards hard. That also means that starting with modern ICs is the right thing to do, probably, when you want to learn how to build a computer like in the 1970s.