My dad is a pretty old man. He is wealthy at least 1-2 million dollars. How should I act after he passes away?

I really love him and as I grew up I understood, that he is not eternal, which males me sad and afraid. What should I do with the money and not just waste it?
I am not saying it because I want it right now, I just don't want to disappoint myself in the first place and him, when he will be looking on me from the heaven.
I'm 20.