Does anyone know the basics of making a working beatmap?

I'm trying to make a beatmap of Kagamine Rin and Kagamine Len's live version of the song "Rettou Joutou Bring It On". Ialready know how to make the actual beatmap, but when I put it into the songs folder, there's an error message. If anyone knows how to fix this, please let me know, as I REALLY need your help. Much thanks, Mr.FrostBite.