This deletes your Parqués account and everything in it: your name, your picture, your flag, your record, your achievements, your friends and your email.
It does not happen instantly — you have 30 days to change your mind. During that time the account is closed (you cannot play with it) and you can bring it back by signing in with your email from the game. After the 30 days your data really is gone, and that has no way back.
This does NOT cancel your subscription. The monthly lives in Google Play or the App Store, not in the game. Cancel it there first, or you will keep being charged.
Type the email and password of your account. They are the same ones you sign in with in the game.