You have a fantastic appetite and a lot of energy I probably should write a book in order to answer you
Let’s do it stepwise.
Here’s my list of recommendation as a start for you:
· Self improvement
Checkout the following channel on youtube. It is one of the most popular medias in China.
罗辑思维官方频道 - Luogic Talkshow - YouTube
In China, people use the audio APP 得到（dedao). It works very much like a podcast but you may have to pay for some of them. Check it out and decide yourself.
Sorry but nothing is at the same time available, creditable, legal and affordable in Chinese language. It is too complex for anyone to have a full picture. Almost the media or propaganda are full of misleading bias. Truth is often banned publicly.
I follow a long list of bloggers on weibo and Twitters myself since a long time, but it might be very difficult for you to start with.
The following writers all have their books translated from English to Chinese. In general I trust their books and you can let me know your feedback. We can discuss from there.
Colin T. Flahive
This one is even more sensitive. There is a full spectrum of perspectives. The famous national propaganda 新闻联播 (xin wen lian bo = national and global news on CCTV channel) is a starting dimension. A few hundred million Chinese people take it as the major if not the only source of official news.
There is plenty of active official account on wechat and weibo.
Use a neutral smartphone (without much private information), register yourself on wechat and weibo. Then you can search for e.g. 大象公会 and other accounts, I may have a long list of recommendation here but depending on what do you want to believe.
We need to be very careful here if the dicussion draw the attention of ccp authorities.
Try to start with a book:
A Short History of Chinese Philosophy Reissue Edition by Yu-lan Fung (Author), Derk Bodde (Editor)
wikipedia is quite reliable and easy to start with but it doesn’t reveal any deep insight behind all the events. Most books are full of lies if published in China.
· Adventure stories
I would suggest you to start with the following cartoons: (Sorry they are all in Chinese but let me know if you have questions) They are all very authentic and interesting.
猴子捞月（I’m not perfectly sure about its name but it can be found on youtube)
You can start by following the following youtuber. I don’t have all the answers for you but a lot of topics are covered here in a neutral but technological perspective.
李永乐老师 - YouTube
There is a biased book 巨婴国. Anyway I recommend you to search for it and read it if possible.
· Chinese culture
What do you mean by streaming culture?
There are full of youtubes but the best ones are always off the TV, unfortunately.
Try 侯宝林 or 郭德纲（Guo Degang ）.
The latter one is the most popular one in China.
· Language learning
- get a chinese boyfriend or girlfriend who is a talkative person with college degree or above. Blabla all the time.
- Live in China or Hongkong or Taiwan for at least 3 months. Immersive learning.
- If you want to learn to read or write, start with Cecilia Norman/Lindqvist’s book
Characters kingdom, Bonnier (1989). ISBN 91-34-50857-0
These are my quick answers to begin with. I need to think how to answer each one of your subjects to give better answers.
Good luck and feel free to contact me.