Once inside, go along the path within and you’ll eventually watch a scene in which Doga will join your party, asking you to bring him to the Cave of the Circle .
Continue and you’ll find a room filled with Moogles. Use the two shops as you will. Firaga is a powerful spell, and Bio is barely weaker than that. Firaga is definitely worth your Gil.
Warp is a low-accuracy Death attempt, though it brings you back to the previous floor out-of-battle so it’s good for that.
Aeroga is the most powerful spell thus far and well worth it, so invest in it as soon as you can!
Haste doubles your number of Hits per attack, which effectively doubles your power for the most part.
Stona cures Petrification, but you could buy 99 Gold Needles, usable by all, for the price of Stona and have change left over! So just buy Gold Needles.
East of the magic shop, you’ll also find yourselves a Fat Chocobo . Use its magical belly as you will. Then go north between the shops to the next area.
In this junk room, go to the northeastern corner and examine the candle nearby to open up the path. Continue along and you’ll end up having to be Minimized to continue . Use Mini, there is no excuse for you to not have this spell by now! Let’s head to that cave.