Learning pipa requires mastering some basic skills, such as correct finger posture, playing skills, scales and modes. Here are some tips for adults to teach themselves pipa:

1. Understand the basic knowledge of pipa, such as structure, range, scale and mode.

2. Learn the correct finger posture, including the posture of left hand and right hand.

3. Learn basic playing skills, such as left-handed fingering, right-handed fingering, string sweeping fingering, and wheel fingering.

4. Practice basic scales and modes, such as pentatonic scale and twelve-average law.

5. Listen, watch and imitate more. You can improve your performance by listening to records and watching videos.