I never had the chance to do somthing then and wanted to know if there was anything I could do now?
What does "never had the chance to do something then" mean? In any event, if the incident in question happened while your son was in school, then we can reasonably assume he was at least five years old at the time. Even if we assume that, under the laws of the unidentified state where this incident occurred, he could have successfully taken legal action when he reached the age of majority, he has been a legal adult for somewhere between six and nine years, so no, it is way too late.
I want to have justice against the school in which was hell for him to pay for almost kikking my son.