Migration of data from CiviCRM Drupal 7 to CiviCRM in WordPress (Version 4.9.4)
You can migrate the CiviCRM data between different CMS platforms but there are several steps to go through.  See Switching CMS platforms and Moving an Existing Installation to a New Server or Location to understand the issues involved.

Make sure you use the same version of CiviCRM on the Drupal and WordPress sites.  You can upgrade later.

Moving other Drupal content to WordPress is a different issue.