There is not the much to know (I hope)
Sigma - is a bond formed by the HEAD-ON overlap of 2 orbitals. [it could be a s-orbital with a s-orbital. it could be a p-orbital with a s-orbital. it could be a p-orbital with a p-orbital(but the head-on overlap)]
pi - the SIDEWAYS overlap of 2 p-orbitals.
A double bond has 1 sigma bond and 1 pi bond.
A triple bond had 1 sigma bond and 2 pi bonds.
and you just have to learn the very simple diagrams for them. overlapping circles. or the figure of eight one for p orbital