I am having trouble resetting my password on my Apple account. And now I have lost my Ipad and I am trying to find it. My kids somehow messed up my password and I can't even change it or reset it. I have tried and tried but it is not working. Help. Every time I do, it says that my password or user name is incorrect.

Its very simple just follow the steps from the below given resource link:
http://support.apple.com/kb/HE36