Square-Enix Help with a battle in FFX

I am at the giant bug thing at the camp, and everytime I play it, I die. Should I level up my characters or is there a way to beat it?

 

Are you talking about the one on Mushroom Rock?

 

Can't go wrong with leveling up.
Level up a bit, learn one or two new abilities, then try again.

 

Yea get further on the sphere grid.

 

Yes, it kills my stongest and my aeons.

 

Not sure if this helps, but I have Yuna, Tidus and Lulu in my party, and before I get to that part of the game I always level up Lulu til she learns her LV.2 Black Magic.. Then I just spam Aeons and Overdrive along with her magic xD

 

Listen, the Sinspawn is quite easy. Max out the Overdrive bars of all characters (summons included) and unleash all them when those two claws in the front aren't protecting it. Beware of the head above! If all the overdrives you slam at it don't kill it, keep wacking it with your two strongest characters (probably Tidus and Auron) and keep Yuna on healing duty, it'll die eventually.