I have studied erhu for nine years, and I will take a professional course this year. Erhu is the most difficult musical instrument in China. If you don't consider the pitch or something, it's ok. If you teach yourself, you can buy "A Simple Introduction to Learning Erhu from scratch", which is a series of books I use to teach cucurbit silk by myself, but I suggest you find a teacher, because sometimes incorrect posture and movements can cause some diseases, such as scapulohumeral periarthritis. I hope you succeed!