First time driving alone and I made a huge mistake. PLEASE help?

Ok so I was planning to just pick up one thing. But when I got there I didn't have enough money. So I was like hey I'll just get a coffee. We'll I lied to my mom saying I was all most home when I was still on my way to get coffee.

On my way to get coffee I didn't know that the lane I was in merged in to the next one. So I pulled right in front of an old lady. She beeped her horn for ever. There was a red light and I look back and she was writing my license plate number down. The thing is the cars my step grandmas. I don't know what happens when people wright your number down.