Blitzes= You can find Blitzes in the Galbadia Garden when your there also on the Centra Plains, i think thats near Edea's house.
Blue dragons= You can find Blue dragons on the Trabia snowfields (but i not sure where, sorry)
Dragon fangs are also dropped by Hexadragons and grendals.
Hexadragons= Esthar in Grandidi forest, also on the Island closest to Hell.
Grendals= Timber Roshfall forest. (but i can never find them there.)
Hexadragons are probably your best bet for Dragon fangs. and there is a good chance they will drop them. can i ask why you need Blitzes? also good luck on getting the items!