hello sir i formate my ipad and i forget my apple id

If you already tried (to no avail) all the steps provided in the support article that led you here (If you forgot your Apple ID), you might encounter "activation lock" status (an anti-theft measure), but neither we, just users like you, nor Apple can help you, sorry, unless you are the original owner and you still have the proof of purchase (receipt/invoice reporting your device’s IMEI or Serial Number). Should be this case, start your request using this link: https://al-support.apple.com/#/additional-support

Shouldn’t be this case, activation lock can be removed only by the previous owner, with the credentials that were used to activate that iPhone/iPad. Without those credentials, that device is useless to you.

You can also take a look at this support article:--> How to remove Activation Lock - Apple Support

Regards

Giulio