How to get my music from my iPhone to my computer iTunes?

So I got an iPhone about two months ago and I haven't needed to plug it into my computer but today when I did it didn't sync my music from my phone onto my computer. I'm trying to get music I have on my computer to my phone but I don't want to delete all the music I have boughten. If I do delete it will I be able to get it back on iTunes on my phone?

Just plug it into iTunes and sync it.

Open your iTunes and connect your iPhone, it well offer you sync options when you plug it in with iTunes open.

Cheers and Good Luck

Just sync them using the cable that came up with your phone when you bought it or you can do online syncing.

Plug it in and sync it