My son ended his life 2 weeks ago. I was his beneficiary on his life insurance policy. trying to have his mail forwarded to me. How do I get P.O.A

You should be able to get either letters of administration issued by a probate court, which would give you the legal authority to act on behalf of the estate. But if your son died with assets that are minimal, probate may be avoided per the state's small affidavit process. So you should pursue the route of a small state affidavit which would give you the authority to receive his mail and collect other important documents.