Talk, it is okay to talk about your dad now or anyother time that you are ready to. I lost my dad eight years ago and I am alot older then you but it doesn't make it any easier. I talk about my dad everyday and I asked questions all the time. You need answers and the only way to get them is to ask. If you can't talk to your mom, then find a grandparent or an aunt or uncle that can fill you in. Coping with death does not happen for everyone at the time the death occurs, sometimes it takes years.
I know that I am not related and can not tell you the answers you need but I am here if you need to just talk about your dad and need someone with an ear to listen.