I don't know how to transfer my music on my iPod to my iTunes

I do not know how to transfer my music (which is purchased) from my new iPod touch to my computer. I have tried syncing them but only my apps are synced and I'm getting angry. I DO NOT want all of m ypurchases deleted since they cost a lot of money. I need help sonce I cannot find it on this stupid website!! Please help.😠😢😕