Will everything be erased? And will I get caught? Ok so I updated and I restored my iPod so everything about cydia on my ipod will be erased? If I go to an airport will they be able to tell that my iPod was jailbroken?
Nobody cares about jailbroken iOS devices.

Even Apple only care if you take it for a warranty repair (as handing a jailbroken device to them and saying "this doesn't work" will probably get a response of "well, you jailbroke it").

I would say relax and don't panic.

To answer the first part of the question, doing a system Restore will remove all traces of the jailbreak. It's MUCH harder to jailbreak an iOS device than it is to remove a jailbreak :)