i dont know apple ipod touch id-user name and password, how do i create or purchase

What do you mean 'don't know apple iPod touch id-useer name and password, how do I create or purchase' ? What are you seeing on your iPod's screen, and what are you trying to do ?

If your iPod is on the activation screen then you will need to type in the account id and password of the account that it's locked to : http://support.apple.com/kb/PH13695

If you want to create a new iTunes account : iTunes: How to set up an Apple ID within iTunes.

Or to create an account without giving credit card details : Create an iTunes Store, App Store, or iBooks Store account without a credit card or other payment method.