There are no free garden pavers available, unless someone wishes to make their own out of concrete using molds. These pavers are not free either ultimately because the concrete and molds still have to be bought in order to create them. If someone is lucky enough to already have these from a previous project or know someone who has them then they may be able to do them for free or minimal cost.
By the time someone buys the materials to make pavers and spends the time making them, they may find a better deal by using home improvement stores to buy the pavers. Stores like The Home Depot and Lowe's carry a wide variety of pavers from which people can choose.