When your spouse or loved one dies, life insurance benefits are not paid automatically. As the beneficiary of a policy, it is up to you to file a claim in order to receive payment. You will need to contact your insurance agent or the insurer and complete and submit paperwork to the insurer.
Life Insurance Claims
Annuity Contract Claims
Accident and Health Claims
Group or Business Insurance Claims
You should contact your insurance company and submit all necessary document.
You can get a copy of his death certificate by going online and getting the address of the "vital records office" in the state where your father lived. Or you could ask a friend or relative over there to get a copy for you. Whilst you are waiting for that to arrive you need to contact Group Life and ask them what other information/proof they will need. His previous employers may be able to provide you with an address if you can't find one online.
The fact that your father died a long way away means that things will take longer to deal with as you will have to wait for paperwork to arrive etc, but don't waste time by doing what you THINK is required - contact the life insurer and make sure you do what IS required. You will definitely need a copy of the death certificate.
Hope it all goes smoothly for you - losing your dad is very hard to cope with without the added complication of the distance involved. Good luck.