How do I use Adobe flash player on iPad

You don't. There is not and never will be a version of Flash that works on an iPad.

There are some browsers out there that allow flash content to play, you'll need to search thorugh the app store for ones that look good to you.

William ~ Welcome to the Support Communities. These related articles may be of interest:

http://www.apple.com/hotnews/thoughts-on-flash/

http://blogs.adobe.com/conversations/2011/11/flash-focus.html