i'm trying to create custom drupal 7 module , in the form setting of the module i have checkboxes wich the admin can select multiple content type

![enter image description here][1]

After installing the module i need to automatically create tow fields (Price of type decimal(4,2) currency of type text) in just to the selected 'content types' from the list above 


  [1]: https://i.sstatic.net/pvsDb.jpg
  [2]: https://i.sstatic.net/J2WyH.jpg