I'm not sure if you've taken chemistry or not, but I'll try to explain.
Polar bonds occur when there is an electronegativity difference between two atoms. (Basically one atom hogs the electrons more than the other atom in the covalent bond). Almost all atoms have different electronegativities. Because of this, most nonpolar covalent bonds happen between atoms of the same kind, like O2, N2, etc. Since in CH3OH, different atoms are bonded together, all of the bonds are polar. There are 5 total bonds in methanol (CH3OH), so it has 5 polar covalent bonds.