I tried the software update on it, and every time it would say up to date. My phone is a Straight Talk phone.I still don't know how to root, or how to use Kies.
Straight Talk doesn't update phones, so you're going to have to go to the S4 section of XDA Forums, find an update for your particular model number S4 and install it. (Back everything up first - you'll lose it all.)