We'll need more information to help you.
First, I can see the RSS feed just fine. What error does it give you?
For MP3s, do you have zaudio enabled? What browser are you using to upload them?
What do you mean "The only file work is for picture?"
He means that the only type of files that display when looking at them are pictures. This is default elgg without any zaudio, video player plugins enabled.
No friends yet.