Oh wow! That sounds really complex. O_O I would have no idea how to do that. lol. When I tried making my own DDR game, I wanted it to be really basic and casual. Just tap your finger to the beat. If you look up the song "False God" from Talos Principle, that's the song I was using for my prototype. You'd tap your finger to the piano.
I do know data management, though. My Brick Breaker game utilizes a simple high score system. It has a save and delete button and when you get a high score, you can type in your name to save that data. If that's the kind of system you want, I can show you the code I used for it.