I don't know if it's been mentioned already but you don't have to work as a dishwasher first to become a caterer.
You can just become a caterer now if you want.
You have a kitchen in your home already to cook in (or your clients home if you are hired) and the internet and a mouth to advertise.
You can start by selling boxed lunches or boxed dinners to people, if you like.
Think about the kinds of people who would need a caterer and try to market to them with your boxed meals.
anyways, just an idea....