Hello Daniel Moysés Kundman,
Sorry for late reply to this,
If you would like to customize all the notification template file, you have to do a lot of file,
JoomlaFolder\media\com_easysocial\apps
-> event
-> fields
-> group
-> user
Example : I select user apps first, inside each folder also have their email notification template file
-> JoomlaFolder\media\com_easysocial\apps\user\photos\themes\default\emails\html\comment.photo.item.php (select photos)
Regarding the user registration email template is under this file location JoomlaFolder/components/com_easysocial/themes/wireframe/emails/html/registration/..
Hope this help.