Is there a way to automatically give certain customers free shipping when they place an order?
You can set up different shipping rates based on customer type. Navigate to Settings / Shipping / Shipping Overrides / Add. Enter the number of overrides you would like to add. Select the shipping method to which you would like your special pricing to apply, zones, ship from addresses, and the customer type. You may override your global shipping setting by quantity, price or weight. And there are many options for your pricing. Use the question mark to guide your choices.