Hi 2belucile. Welcome to DC. Here's a link explaining what buttermilk is: Buttermilk
When I don't have buttermilk, I substitute soured milk. If the recipe calls for 1 cup buttermilk, you can put 1 tablespoon lemon juice into 1 cup of plain milk. Let sit for a little while until it curdles a but, then use it. It works just fine.