How to switch all my info from one iphone to another?

How can I switch all of my stuff on my iphone to another iphone cuz my phone is really cracked and stuff and my sis just got an iPhone 6 so I wanna switch to her old iphone because that one isn't cracked (btw I have a verizon, i don't know if that matters or not) so how do I switch them? Do I have to call verizon? Or can I just do it straight from my house?

You can use icloud, or itunes(which you need w computer for). ICloud backup your previous phone and then restore from back up on your new phone