Item with Free shipping plus item with Paid shippi

I have an item in my store for which shipping is free.
I also have other items for which shipping is paid.

How do I configure the item with free shipping so that the shipping address option is shown at checkout?

You could set a volume (dimensions) to your paid shipping items and no volume for the others. Then, in the free shipping method, set a maximum volume of 0.01 and a minimum volume of 0.01 for the paid shipping method.

Then, the system will show only to appropriate shipping method based on the volume of the products in the cart.