Don't know of anywhere that offers such classes. But YouTube has a wealth of information, videos, examples, and covers just about any topic, repair, item, make, model, or style of anything you can think of ... repair, fix, or how to!
YouTube is great. But I will admit, sometimes I wish the posters of the videos would just get over the initial BS and just get on with the topic under discussion. But, be patient and sift through the muck-and-gunk. And compare videos too. Sometimes it takes more than 1 to get the full picture.