When a recipe calls for blind baking a pie crust it’s referring to baking the crust before filling it. Often this is done to help prevent the crust from becoming soggy when you bake it with the filling. To do this you need to line the dough with parchment or aluminum foil so it completely covers the dough, and then fill it with pie weights.
Kitchen stores sell pie weights, but dried beans work great and are much less expensive. I keep my dried bean pie weights in a container labeled “Pie Weights” and use them for that specific purpose. I don’t recommend cooking the beans you’ve used as pie weights, as the flavor is thrown off by baking them dry. However, as long as you carefully remove them from the baked pie shell, you can continue to use them as pie weights. I’ve found lining the pie shell with aluminum foil makes it easier to remove the pie weights at the end.