Hi @Crabbnebula, you certainly have your work cut out for you.
Mine is a 1990 so I am thinking many of these problems will be different on mine as they did away with the CRT in 1990. However I would suggest you pick up a factory service manual off ebay. There is one on there right now for about $70 https://www.ebay.com/itm/184451391576?hash=item2af228e058:g:VpgAAOSwhXBfYyhG
I have the service manual for my 1990 and it has a very detailed extensive electrical diagnosis section with a lot of wiring diagrams, test procedures, etc.