Warp Plates can be compared to teleporting pressure plates. Stand on one and you will get teleported to another warp plate. Warp Plates are attuned to each other by inserting the Attuned Shard of another warp plate.
After placing a warp plate, right-click, and you will see it creating an Attuned Shard. This shard is bound to this warp plate, which means you should take it with you to another warp plate. To create a two-way connection between two warp plates, simply swap their attuned shards with each other, so that Warp Plate A contains the Attuned Shard of Warp Plate B, and vice-versa.
Once a warp plate has been bound to another warp plate, you can simply stand on it to get teleported to its counterpart.