"download a store-bought CD"?
When you buy a CD from the iTunes Music store, it will definitely come with track names, album art, etc. If you buy a regular CD and rip it to your computer, it SOMETIMES will give you the track names.
If it doesn't, the only method I know is to manually put in the names. Not so bad really - highlight them all and hit command+i (or right-click + Get Info) to make large changes (i.e. all one artist, album, etc.). For individual track names, you can do Get Info for each song or just do a "slow double click" on the song name to change it.
Hope that helps! 🙂