Can i suggest (give any advice) to improve GoDot engine? (interface, scripting usability for ex.)
There is also the Godot contributors chat: https://chat.godotengine.org/home
If you've got something very specific in mind check with them and they'll tell you, if it's something that needs to be added or changed they'll tell you to make an issue on the Godot github.
For the engine? https://github.com/godotengine/godot-proposals/issues/
For the engine website? https://github.com/godotengine/godot-website/issues
Q&A? No idea, probably the above/previous link will do.
For the forums? Here.