know somebody where can I find notes for song?
I guess that you know the name of a song, and want to find the notes for the song.
Sometimes, a musician will create a MIDI file of the song, and place it on the Internet. That may, or may not, be allowable under copyright law.
One way to find songs is to use a search engine, such as Google. Search for the name of the song, and also use "MIDI" in the search.
Another way is to guess the file name. If the song has a simple title, such as ""Please please me" by the Beatles, you can guess that the file name might be "Please_please_me.mid" and search for that.
There are also indexes of songs, but I do not recommend any one in particular.