Do I need to install IOS 7 on my iPhone?

I'm getting my iPhone 5 today I'm wondering if ill need to install IOS 7 or will it already be on there when I get it? Do I have to have IOS 7?

You should apply the iOS 7.0.6 update if it doesn't already have it. It patches a serious bug.

If you bought your phone from Apple or your carrier, and it's new, it will (or should) have iOS 7 already installed on it. You'll want to check for any updates and install them as well, such as the recent iOS 7.0.6 update, which fixes a security issue.

I agree with the others. It should already have the newest version of iOS, but if not you can download it via Wi-Fi.

To check or download new update, go to:
Settings
General
Software update

Then if you need to download it, you should probably back up contacts because it tends to delete things

You don't have to but I would since most apps are written for 7.
I would also go to General, Accessibility, Reduce Motion, and turn it on, that gets rid of all that motion and its far better imo!