Well, at least you didn't say you died while fighting the first boss. Because in all the history of people playing FF, I don't think that's ever happened.

Anyway, this game has one and only one solution to advancing when the going gets tough: level up. Gain 2-3 levels and try again. Still can't do it? Gain 2-3 more, then try again. etc. Eventually you'll get through anything.

And since I don't want to assume anything is too obvious, it's a good idea to equip your party and all that, too.