If I restore my iPhone will my software data change?

I now have a new iPhone after my previous one froze and stalled on me. If I back my new iPhone up to iTunes will it change my IOS software? The 6.1.3 caused my iPhone Wi-Fi to black out will it happen again?
I want all my old contacts, etc

Added (1). @Koo will it automatically update the software? Or do I have a say in that? Because I don't want the update

As long as you back your iPhone up in iTunes, making sure all your contacts are also backed up you can restore your iPhone without worries, Your iPhone will then be back to factory settings with the latest software (if available).

Hope this helps!