Hi @acombs1793, welcome, and thanks for the purchase. As @DOS76 states above, you can basically just delete the LaunchBox.xml file (and any images in the images folder) if you want to start over fresh.
Typically, if you're getting 0 games imported, it's because the games you're trying to import already exist, but you're not seeing them for some reason. Sometimes this happens when you delete a platform which orphans the games (makes them not belong to any platforms, but they still should show up in all games).