I live in Florida and am executor for a will in probate in NJ. Do I need a lawyer licensed in both states to help me file tax papers

Unless there is property to probate in Florida, probably not. If all the property is in NJ, the NJ lawyer may set it up so you get sworn in as executor in the FLA probate court, to save some travel time. THe FLA probate court then sends your papers and sends them to the NJ probate court who admits them and certifies you as executor. But needing a FLA lawyer with no proeprty down there, i don't think.