Asphalt 8 I got on a account not mine how do I get off?

[Windows Central Question]

Okay so I got my laptop, recently updated to windows 10. I got asphalt 8: airborne on my laptop that my dad bought off of ebay. They asked me to choose an load for it. I clicked iCloud. It took me to an account not mine it was Portuguese. I changed it to english and raced two times. Cause it seemed cool that he had millions of money and lots of cars. But, I know I did the wrong thing and I want to get off.. Help? :C