No, you absolutely do not need to know transition metals
you must know that, in order:
elementals have an oxidation # of 0
F, in a compound has an oxidation of –1
H has an oxidation of +1, unless bound to metals
O has an oxiation of –2, unless its a peroxide, in which case it is –1.
should probably also know that alkali and alkaline earth metals are usu. +1 and +2