My father died of a sudden heart attack when I was12 years

When my father died and unexpectedly at the age of 12. I was too young to ask about what happen to his bank accounts & the money that we're in those accounts. My mother went mintally I'll and doesn't remember anything. My other family members took care of the funeral arrangements but also took full advantage and took all of my fatehers collectable items. He collected antiques, tools, guns, cars, & jewelry. They also took all his credit cards and left us with nothing. I knew my father very well and he was always looking out for our best interest and future. He also was aware of his heart condition and that he was gonna have to be leaving us sooner than he that. Which made him very sad & extremely worried. Which makes me think now that he just might of left me or us a life insurance policy. I know the both banks he banked with and the years of when he banked. This has been nagging at me for years , untell last night when a friend suggested to me that I should look into it. If its not too much trouble can someone help me find out. We have struggled mentally, emotionally, and financially. Me my mother and Lil brother and sister. For some reason the nightmare that came into our live the night he pasted so sudden so fast so sad unfortunatlly I still live with till this day. So many un answerd questions. I would at least love to get an answer to this one that am writing about. Thank u