I never tried it myself, but I know there is a software called "Band in a box" - just google it.
You feed it some chords (like, c, a, etc.), choose a music style, instruments, and it will use prerecorded samples and loops to create the music. Et voilá, music without playing an instrument.
Of course this will sound a bit generic, but you will get something to sing to much sooner and easier, than by waiting until you have learned an instrument.
There are also similar products for some instruments, EZDrummer2 for drums (I use that and love it!), EZkeys for piano etc.
Good luck, Bye Wolfi