Hi, thanks for your question :). Tbh I’m not really qualified to teach Korean and I’m only intermediate level myself. I especially couldn’t help you with pronunciation or spotting your mistakes like a native or professional could! I wouldn’t want to risk teaching people incorrect or incomplete information. Honestly, I’ve seen other people on tumblr doing that quite often. There are a lot of good websites which provide (free) lessons online already though and that’s how I learn myself (check my /tagged/resources).
I’m happy to tell you what I know if you have specific questions though! I actually have considered getting qualified to teach Korean in the future since I love teaching, and the Korean language, but I don’t think I’m able to do that now!