I can answer questions regarding the care and propagation of cactus and succulents and would actually group these together as folks often mistake one for the other and often their care is quite different. I also have a cold hardy cactus and succulent garden that has been quite successful. The subject in regard to classification of type is enormous and I wouldn't be able to answer all questions by any means. It is really IMPORTANT TO INCLUDE A PHOTO if at all possible and LET ME KNOW WHERE YOU ARE FROM, especially in terms of climate.
I have learned by reading books, by trial and error and by consulting with folks with much more knowledge. I have primarily grown C&S for the last 20 years.
Cactus and Succulent Society of Massachusetts.
No formal training. See experience.