There is a state will code, and duty sworn to the executor. If you search your state or contact the courthouse register of wills office they should have a copy.
There is a priority that it is paid. The executor can not just pay willy nilly. The attorney that probates the will has the executor take the oath, file the income tax forms for the worth of the estate. The ad will go in the paper for three times.
Any bills for the burial, or as the father requested be paid. In his insurance policy he may have liens on it, or directions.
If there are credit cards and no death insurance on them, the executor receiving the mail will pay them. If there is no money to pay them they will get nothing,
Unless there is a home or assests, then all creditors then heirs get theirs.,
That is why the executor gets a fee from handling the mess some estates are in.
The heirs can not be sued for the money unless they sold property and creditors go after that.