How do I get my share if my dad’s will states that on his passing, his estate would be divided up equally?

If the CD was titled jointly, it passes to the joint owner upon the death of your father. It does not pass through the will to the heirs. You need to talk to your brother about sharing it. He has not legal obligation to do so but may do so out of fairness. If he will not, you need a lawyer to file a petition challenging the transfer.