One or the other of you needs then to file the necessary papers in a court of law. This is done at the "state" level, as the rules and regulations of your particular state will prevail through the...
Under the law a divorce is the official determination by a Judge that the marriage is over. There cannot be a divorce without judicial intervention. Antolin Andrew Marks.
You get a job. If you have children, you force your spouse to pay child support plus 1/2 medical expenses plus child care (try to get 100% since he wants the divorce) plus 1/2 school expenses plus...
In the U.S.A., the age of legal adulthood is 18. So, if a 19 year old signs any kind of legal contract, it is binding and the sole responsibility of that 19 year old. The only instance I can think of...