Yes (and no). You can prepare the ground beef mixture, allowing it to cool completely and have it set aside in a covered bowl or airtight container in the fridge for up to 5 days. You can even have the cheese shredded in advance in a similar style in the fridge for up to a week or two, but I do not recommend assembling the nachos until you’re almost ready to serve. If you prepare the nachos on a baking sheet, cover with plastic wrap and store it in the fridge, it can be okay for up to 3 or 4 hours before heating, but anything longer than that can possibly result in soggy or stale chips, which we’d like to avoid when possible.