In that case, you should really use a Managed deployment and create a security profile that prevents people from erasing, resetting, using their own AppleID and so forth. Out of the box, the device is intended as a single user device and anyone who can get a hold of it, and unlock the screen, has a large range of things they can do.
At the very least, put a restriction passcode on it. Lock down changes to accounts, share my location, location services, installing or deleting apps, disallow in app purchases.
Use an AppleID you own, but do not use for anything else, and signin to iCloud with it and enable find my iphone before locking down changes to accounts. Turn off all other iCloud settings (photo's, contacts, apps, notes etc - just leave find my iphone on. Then disallow changes to accounts in restrictions.
You can only use a four digit passcode for the restrictions passcode, so pick something that no guest will easily guess. Obviously, you cannot set a screen lock passcode, so be prepared for people to set one and leave or forget it, requiring you to restore the device in itunes often to reset it to none, and then set everything back up from scratch.