I think the $50 I said was stolen out of the car wasn't really stolen
What do you think happened to the $50?
I think I spent it. And I'm too embarrassed to tell anyone about what I did
If you are mistaken, hen correct that mistake immediately. You could get someone in trouble if you don't.
Wait, I'm too embarrassed to tell my dad about it. I'll say I didn't have it, so what's the big deal?
You are advancing a lie to save yourself from embarrassment. That's wrong and selfish. Be upfront about your mistakes and learn from them.