If I was further along in my career and realized the level of abuse I experienced then, I would have sued these people. We're talking comments about your race to explain poor performance and collection tins appearing on your desk that say "Plastic Surgery Fund."
There is next to no training, and you are often expected to jump through arbitrary hoops to please two owners with very different expectations.
You learn by trying to do something, not doing it right, and then getting berated for how it should be done and repeating. Don't work here unless you're desperate for the money.