I took out my fake ID and gave it to the cashier.
Why did you give the cashier a fake ID?
I want to get the price down a few dollars
It's wrong to deceive someone with a fake ID. If you are caught, you risk getting arrested for fraud. If this happens, you will have destroyed your life just to save a few dollars.
I'm young and I don't care I'm going to do what I want.
I can understand you are young and you think you can do whatever you want, but there are rules there for a reason. You should not deceive someone with a fake ID. Be honest with others and your dealings with them.