It is recommended to practice some simple songs first, such as Yang tunes and the like
From bottom to top, they are the treble area, the alto area, and the bass area
C key: Two dots on the top 21 One dot on the top 65321 No dots 65321 One dot on the bottom 65321 Two dots on the bottom 6532
D key: Two dots on the top 1 One dot on the top 65321 No dots 65321 One dot on the bottom 65321 One dot below 65321
G key: Two dots above 5321 One dot above 65321 No dot 65321 One dot below 65321 Two dots below 65
For fingering, some elementary songs will have one Mark each place
You can buy a "Chinese Guzheng New Zheng Grading Tutorial". The songs in it are divided into levels. There is an appendix at the back of the book that explains all the symbols, their meanings and how to play them.
It is best to find a teacher, self-study is not professional after all