more about people who make stuff, sell stuff, and buy stuff

My husband bought me an mp3 player for my birthday and I have music on my computer.  We bought the player.  We bought the computer.  We buy the service used to download the music and paid 99 cents or $1.29 plus tax or something like that for each song, but is it ok to transfer the music to the mp3 player?  I know I sound like an idiot, but I'm old and technologically challenged.  I know people share music and rip and burn discs or whatever the proper word is.  I also know that when I used to buy records(back in the vinyl age) I could play them on any record player I owned.  Or I could take them to a friends house and play them there.  Didn't need to copy them, they were portable.  I suppose there were pirates back then too but I never knew about them.  But now days it's so much easier to steal someone's creative work.  No one buys records or even cd's anymore.  Soon no one will buy books anymore.  We will have to download them onto something.  I love reading books.  And I am hoping that that process of purchasing electronic books will be easy and not too expensive, cause this old dog isn't getting any younger and I'm not sure how may new tricks I can learn.