If you go on craftsy.com they have an entire section decorated to cake decorating. It’s all online tutorials that you can do at your own pace, ask the instructor questions, watch as many times as you want and even take notes. There’s a class on running a cake business, everything from coming up with a name, health regulations, tips, etc. Last I checked it was under $40 and you get to keep the class forever once you buy it. Might be worth checking out :)