Unknown Coins

Here is my story, I began to collect coins when I was 12 years old not very old but it just happen to be my hobbie. I took some of my grandpa collection when he passed away. After, those years had pass. In 2002, I began to review my coin collection, so I laid them on the white carpet. I found 2 coins from my grandpa collection is really rare especially 1790s. He was a  bounty hunter during WW1 and WW2. My grandma told me alot about grandpa.

Her is my real question where can I sell those valuable coins? Please comment.