1. Looking for Chinese information (few, here are some, not all)
2. Bite the bullet and read the official documents (Not good in English? Much better than not speaking. Technical documents are much easier to read than academic documents, and you can learn English by the way)
3. Really can’t read English documents? Just look at the code. (Requires a certain amount of skill)

The second method is recommended. After reading the document, take a project and practice it, and you can basically get started.

drupal8 is based on symfony, drupal has a lot of information; you can refer to it;