I was purely self-taught and didn't know the score at first. My experience is to find a simple music score practice, learn music theory while practicing techniques, and then practice slowly on difficult songs. I remember that the first song I practiced that year was "Kangding Love Song", which was relatively simple and didn't need to be changed, but it was better to find someone to bring it. I didn't find anyone to bring me, so I bought a simple erhu introductory course, which was not bad. Another thing is to find a simple erhu.