Broken Yaml file after pasting code

I just try to add my firts code to tha yaml file from a forum. And when i try to validate it i got error:

end of the stream or a document separator is expected at line 3, column 1:
default_config:
^

Im really new to this and having a hart time to find the problem.
Can someone please take a look at this and help me out.

The very first line of your config needs to be removed. Not sure what you were trying to do but that is the issue.

It was there. Cant remember if it was befor i paste the code… Ill try thanks !