Zend certified PHP/Magento developer

Magento 2 add custom fields to order create in admin area

How to add custom input and drop-downs order create in admin sales order creation.

I want to add custom field hopefully a new section where when we create a custom order through admin only we can pass custom values to it.

I am not sure if I am creating a custom attributes.

Please can someone provide me with any tips or where to look