How can I find out about a will from abroad?
Your are in a very difficult situation. To find out about handling an inheritance when you live abroad is not easy. Do you know if there was a probate proceeding filed for your father's will? If there was a probate proceeding, there will be a court record of the will assets. But to locate that proceeding, you need to know the county in the U.S. where the proceeding was filed. Then you have to obtain the case number. Then you have to look the case up and read the file. All this would be difficult if you lived in the U.S., and much harder when you live abroad.
Perhaps there was no probate proceeding, because all your father's assets disappeared before his death. Or perhaps they disappeared after it, but nevertheless no court proceeding was held.
Unfortunately, to try to learn what actually happened, you'd need to hire and pay for a lawyer,and perhaps a private investigator as well. That's a substantial expense, when there's surely no guarantee you'll obtain any money back.
Sadly, there's often much truth in the maxim "possession is nine/tenths of the law." It's unlikely you can change that truth in this instance.