All you really need is FL, a midi controller (just any old MIDI keyboard will do, I prefer two octaves+ to experiment with chords) and a MIDI cable. Then get some VSTs into FL and try it.
Above all else, you'll need a lot of perseverance. I've tried this before and it's really easy to give up after a few bad attempts. Just remember that if your 23rd mix is the brilliant one, you'll have to get through the first 22.
Good luck!