You don't tell us what computer you are using (or tablet or smartphone etc).
However if it is Windows then download the mp3 files from the email to your computer hard disk.
Then open Windows Media Player and select the mp3 files then use the Burn option to copy them to CD.
I assume you want to put the mp3 files on the CD as actual mp3 files, if so put them on as "data" files.
If you want to put them on in "audio" format, so they can be played in a normal CD player, then put them on as "Audio" files, though you can only put 60 minutes of "Audio" files on a CD.
If you put the files on the CD in mp3 format you can still play them on a computer, and some *SOME* CD players, but some CD players will not play mp3 files they only play Audio files.