Is there anything that will block a magnetic field from a magnet

Yes, there is a material called mu-metal. but it's not a complete block. It reduces the field by a large factor, depending on the thickness of the mu-metal shield.

No, nothing can block it. However, as pointed out above, there are things that can shield something from a magnetic field. They do this by bending or diverting the field around and away from the object.

Any conductor can do this to a degree and mu-metal is an excellent example of such a material. Superconductors obviously being great at it as well.

Yes, anything that is in a superconducting state. It is very well known that superconductors pushes out all the magnetic fields inside them. If you are interested, the effect is known as the Meissner Effect.