First day on Job bad job

I Shadowed For one day counting money and doing accounting paperwork. Today I was thinking I was going to shadow again. But the man told me to try it myself and then he left he by myself. I made a mistake and the money was $100 short. The man eventually came back to help me fix the problem but now I'm embarrassed and I know the Mann talked about me to everyone. What's the mature way to handle this