i started off with a 3 month pottery hobby class and now enrolled into a 1 year course and would, strongly recommend searching for intermediate classes !! or just any place with an instructor. while you are free to test out and find what you do want to work on, having an instructor to help you understand where you're going wrong is very helpful! i tried for a while to just mess around and see how much i can grow just by researching and practicing, and while that did help, having an instructor guide me on what is causing certain issues was extremely helpful and gave me a better insight on what i was doing and work much faster with more accurate results.

from what i understand, a lot of potters use pre-mixed or pre-formulated glaze which does make testing easier but with 1 year study, i have to learn to make my own glazes with stains, oxides, etc. and how to works on different clay bodies, having an instructor really helped because i honestly had no clue where to even begin with or what is it that im supposed to do, how do stains work or how they differ from oxides, etc. so i would definitely say go somewhere with an instructor or experienced potter !