I would do whatever I want!
What would you do if one day your parents came into your room and said, “Today is your big day! We’ll let you do whatever you want to”?
I would definitely make my parents do all sorts of crazy things, like: make them go to the most expensive shops and buy me lots of treats, get them to buy me loads of cheese and onion crisps. I would lay on the sofa watching TV for hours and hours, eating my crisps surrounded by my expensive treats. Meanwhile, my parents are looking for the coolest funfair in the Universe for me to go to, where the roller coasters are the biggest, most thrilling, fastest rides ever!