Start page count from 1 with views pager
To change it just on the UI, you can adapt the number in template_preprocess_pager in your theme's .theme file.
Something like:
function template_preprocess_pager(&amp;$variables) {
  foreach ($variables['items']['pages'] as $key =&gt; $value) {
    $variables['items']['pages'][$key]['text'] = $key +1;
  }
}

To change the query params, you could use hook_url_inbound_alter and hook_url_outbound_alter to manipulate the queryparams, but this was D7.
In D8 you would need to go in this direction to manipulate them: How do I implement the equivalent of hook_url_inbound_alter()?