So-called "cautions" are not violations of criminal statutes and thus do not (SHOULD not) appear on your criminal record. In my experience these "cautions" are only kept in local files which are used...
It depends on where you are. But police headquarters in your city is the best place to start, since that's likely where whoever needs your criminal record will go. Call and ask them where to go....
Criminal histories are public records. Go to your local law enforcement agency and request a check of the person. Youwill need their full name and DOB. It will probably only cost you a small...