Yes, you can.
We call this the product Preview mode. When adding/editing a product, you can set its status. By default, the status is Active. Active products (within their availability dates), are visible to store shoppers, and can be placed in the weekly newsletter.
But you can also set the status to Preview. Only store managers can view the products with a status of Preview. Regular store shoppers will not see them.
In addition, when viewing the product list, the Preview products have a small green icon in the top right corner to indicate that they are in Preview