Q: How do you use iCloud back up system on an iPod touch?

I'm getting an iPhone 6 but I recently had an iPod touch 5th generation with an iOS 9.3 update, but I want to back up all my data and put it on my iPhone but I don't know how to do it. Do I pay for it? Will it back up everything I want it to? HOw do I know it will work right?