They do, if they're not licensed.
no you dont
i really dont know if you can do that
Even if you buy a recording of a song, you've only paid for that one instance of it; copying it (say, to share with a friend) is copyright infringement.
I dont want to be lonely
That would be copyright infringement if the original song was protected.
You can only copyright a song if you are the song's author. You can't copyright someone else's song. Although the author can sell you their copyright.
Each song has its own copyright year.
It is probably copyright infringement. There are exceptions, though.
The only way to be certain is to contact the copyright holder yourself.
If you are not the composer of the song then you can NEVER take the copyright as yours; you would have to purchase it from the copyright owners. Also, when the copyright expires, 50 or more years after the author's death (or after publication, depending upon circumstances and national laws) it is no longer copyrighted at all and nobody can possibly own the copyright.
Short phrases like song titles cannot be protected by copyright.
You can't. It is a right that the writer owns. You can offer to buy the copyright.