1. You should be able to transfer all of your mp3 songs that you have on your computer. As long as you copied them from your cds (I saw your other post) and they were DEFINITELY mp3s (check the file extensions), you should have no problems with "permissions." As long as you didn't purchase digital downloads before let's say...a year ago from somewhere like iTunes, then you will have no problems. If you're very new to mp3s then you probably have no need to worry.

2. If you are talking about an aux input, then you will be able to plug the player into your car. The cable that you will want will have two male ends of the same size. One will plug into the headphone jack of the player and the other will plug into the aux input. If you go to your local Radio Shack or similar store and ask for an aux cable, they should know what you're talking about.

The link from Amazon I'm including is to the type of cable you'll need, but you don't need to spend $$ on it. I'm just using it because it has a fairly decent description of what it is.

http://www.amazon.com/MONSTER-123870-Feet-Monster-Icable/dp/B000V8WO1O/ref=pd_cp_e_1