trouble downloading apps like Pandora
there is no item called software update in my general settings. I have an older phone.
iPhone 3G, iOS 4.2
You won't see this without iOS 5 or higher. If you have a 3G you cannot update beyond iOS 4.2.1. If you have a 3GS you can update using iTunes, as explained here: http://support.apple.com/kb/HT4623.