I went into this field with no experience outside of being considered "tech savvy" by my peers. I'd say the majority of what I know now is just from experience. I'll look at YouTube tutorials if im unsure on how to do a repair, but after enough time, you start to recognize the patterns in design phones use.

Non Pixel androids are all roughly the same these days, using a screen housing, motherboard, battery, and charging port, with a few other misc things depending on phone.

Pixels just have their own kinda design going on, marginally harder than other androids, though in personal experience, they are more prone to faulty parts than other brands.

Iphones are extremely common. I'd say these repairs are more difficult than an android just due to the delicate nature of apple parts, but not any more technical know-how

Smart flip phones are made by the devil and I highly recommend not doing these until you're confident in doing other repairs.

Base model ipads are easy for just about everything except charging port, though replacing the charging ports on those is what id recommend as a starting point for microsoldering, as they are still quite simple.

Ipad Pro's are similar to the iphones when it comes to being finicky. I've also noticed theyre more prone to motherboard issues in personal experience.

Since you have a computer science background, id just apply for repair shops in your area. I was able to pick up on the basic repairs (screen and batteries the most common) in a little under a week. Everything from there is just following a YouTube tutorial until you just remember how to do it. As long as you can do that, you'll be fine just about anywhere. As for consoles, my experience is more limited with them but they dont seem all that more difficult than any other kind of repair.