It means for whatever reason you cannot connect to the game's servers. Could be it's down, you have a firewall, or you just can't connect.
Right click on the launcher and try "Running as Administrator". Hope that fixes the issue.
why is the game in chinese, how to fly?
The game is Chinese, because they are the original creators and the translation job has been happening, but it can't be done in one day as you can surely understand.
You can't fly with a natural ability, at least for now, since those features are still being worked on (Coding, etc.). However, you get a few green scrolls which will let you fly for 3 minutes and enjoy the experience.