How to only have 3.1 gbs left on my iPhone 5s that I just bought last night. Read below?

I bought my phone yesterday. It is a 16 gb one. It says I've used 9.1 gbs and only have 3.1 left. I have no apps downloaded, I have no photos yet. I'm signed into iCloud so I could have my contacts saved from my old phone. I've barely used my phone. I updated it to the new iOS 8.3 or whatever. Why is it doing this. Is something wrong with my phone

Go into "settings", "general", "usage", and "manage storage" and you can see what is taking up your memory.