Where do you find spells in final fantasy 3 ds?

Answer 1

You can find most spells in Doga's Village down on the Surface World. Otherwise, normal spells (by that I mean level 6 and under black & white magic) can be purchased at normal towns in the magic shop and level 7 & 8 black & white magic can be bought at Doga's Manor. The levels 1~5 summoning spells can be bought at Replito and the level 6, 7, & 8 summoning spells can be obtained by beating the actual monsters if you want them earlier, or can be bought at Eureka near the end of the game, so I recommend you to beat the summons for the level 6,7, & 8 summoning spells.

Answer 2

The Blizzaga spell is found in a treasure chest in the Cave of Tides.