Oh wow, that sounds really intense! Most of what I know now did come from trial and error, but it was of my own accord so the environment was low stress. I couldn't imagine doing anything with cake under pressure; I'd be a damn disaster, lol. Sounds like the best way to go about it is to work in a bakery though. The tools I have are so limited (and a little pathetic) that I'd never get anywhere unless I just jumped right in and work my way up to decorator.
I'm also kind of a crappy baker? Like there's a chance the cake will look decent but no promises that it'll taste any good lol. So right now it doesn't make much sense for me to practice on my own since the results might not even be edible. And I'm paying for ingredients and tools and everything so it's a little silly for me to just decorate cakes and toss them.
Yeah, working at a bakery is the best way to learn. HOWEVER, not all bakeries are alike! Ours is pretty high stress, and there are some that are even more people and demand, but on the flip side there are much smaller ones or less stress ones. A lot of people who have come into work and ended up quitting came from a smaller bakery, or a walmart bakery and been alarmed by the pace and demand of ours considering how physically small and how few people we had. So if you wanted to work at one just check them out and see what the demand is usually like. However, some bakeries like walmart are low demand BECAUSE they are poor quality, so you wouldn't learn too much that way.
I'm not sure how it is everywhere else, but I don't bake the cakes at all! We have actual bakers one one half, and decorators on the other. There are floaters who do both, but for us it's normal that a decorator doesn't deal with baking, besides being able to tell if a cake taste/looks/feels right when we set them up. I've dropped some sugar cookies on loan because I am the etc.
(I have something to admit...my job title is not actually cake artist, it's cake artist support. I guess I'd call it a jr decorator, but I'll get loaned to the bakers for dishes/stacking cooled cakes if they're low staffed.) So I don't think you have to worry about actually baking to be a decorator! We have a few people who will just order blank cakes for them to decorate if they are event planners and such.
You can also order
cake dummies, that are just circle styrofoam that doesn't shed. If you put a small weight on top of those to hold them down while you ice them, as long as you nail them to a board you can decorate them and move them, and just scrape off the icing to do it again. That's how my co-worker learned how to do it at first workplace, I just got thrown into doing full cakes from the start. The steepest cost is the materials. When you're learning you should just use white, and use a canvas piping bag so you can wash it out instead of throwing away the plastic ones.