Your English is a little tricky, but I'll have a go..
You have a demo of your songs that are on a cassette right now...You want to transfer your cassette recordings to CD.
You should get a software program to act as a go-between so you can edit & clean it up a little bit before you transfer it to CD.
I suggest Sound Forge XP..It's about 50 dollars US..
Any more help needed, let me know..
DJ