Like many wedding couples, you've picked songs with great lyrics for the message between a new bride and groom. But not the best for your "first" dance. Professionals could certainly perform beautiful lyrical stuff to either of these songs, but you likely cannot. A very slow Fox Trot, with the sway step being the most prominent, might work for the Tim McGraw tune. Not sure on the Buble tune, it's a jazzy number, but you may be able to come up with something on your own. Or someone else may figure on a decent dance that would work. I have not heard that one enough, to be honest. But my suspicion is that a rumba won't quite work. Maybe tango, but I'm just guessing.
Either way, good luck and have fun.