you have to go to nation rules and then use existing nation, and add leagues and cups to existing structure. then you add your league onto the bottom of it and save as in your editor data folder. then when you go to start a new game make sure you tick the change option when selecting which db you want to run it on, this will take you to a list of db's you have made and/or downloaded where you can chose which files you want to include in your new game. btw fm can run both dbc and xml files as database files the only difference is that one is compressed and one isn't.