First ,was the seller from the same state? If not, you don't even want to start this. It is against federal laws to transfer a handgun across state lines without involving a dealer with a FFL. Both parties would be in a heap of trouble in that case/
from what I have been reading, there is no requirement to register a handgun in Utah. Where I have been looking may be outdated though. Do you have something more current that requires registration?
I'm not sure I would admit I bought a gun when you were not old enough (although from what I have found, it is legal at 18 to by a gun from a private owner). Utah seems to be pretty lax about their gun laws but admitting to a crime is rarely a good idea.

