Wich template to override for user account form
use the native interface to add fields and change display

/admin/config/people/accounts/fields

/admin/config/people/accounts/display/full


if the html structure need to be changed , the template 


  user.html.twig


can be override in the theme child templates folder.

As an exmaple for custom added individual fields, with fundation classes :

&lt;article{{ attributes }}&gt;
  {% if content %}
    &lt;div class="grid-x grid-margin-x"&gt;
      &lt;div class="cell small-12 medium-6 large-3"&gt;
        {{ content.field_user_photo }}
      &lt;/div&gt;
      &lt;div class="cell small-12 medium-6 large-9"&gt;
        {{ content.field_user_name }}
        {{ content.field_user_status }}
        {{ content.field_user_email }}
        {{ content.field_user_phone }}        
      &lt;/div&gt;
    &lt;/div&gt;
  {% endif %}
&lt;/article&gt;