1) The nucleus has spin I=1, so three possible values for m=-1,0,1. There are only 3 hyperfine levels, a possible explanation is that F=1, this means the hyperfine field has J=0,1 or 2.
2) At low temperature, the nuclei will mostly be in the state with the lowest energy (here m_i=+1). The distribution of nuclei will (classically) follow a maxwell-boltzmann distribution. So there is a preffered orientation for this ensemble.