Hi Lewis, great question! This is something that likely varies business-to-business.
I think what you may be looking for is a Stage, the culinary equivalent to an internship. Many restaurants and other food service businesses offer these opportunities, although they tend to be more commonly offered by higher end establishments.
The steps for finding an opportunity like what you are looking for can vary as well.
One way is to enroll in a culinary arts education program. There are numerous private culinary schools around the US and the world, which offer degrees or certificates as well as career counseling to help you find stage and job opportunities. Additionally, there are many community colleges in the US with robust culinary programs, usually at the AS degree level, which tend to be more affordable and accessible. I'll also mention that some four year Universities offer BA or BS degrees in culinary fields, including Johnson and Wales in Providence, RI.
The final thing I will mention is that many restaurants will be willing to offer positions to people like yourself who want experience outside of a formal program. Because it food service is a high turnover industry, it is fairly common for people wanting kitchen experience to join a restaurant in an entry level dishwasher or prep role and quickly move up as positions open and the chef needs someone to quickly take over cooking tasks.
