404 Error Accumulated

Hi,
I accumulate many 404 errors on my website, which are of technical origin. Some of them:
/templates/system/css/system.css
/admin/images/cal_date_over.gif
/vendor/phpunit/phpunit/composer.json
/assets/frontend/jquery_update/replace/ui/ui/i18n/jquery.ui.datepicker-ru.js
/wordpress/wp-admin/install.php
/assets/frontend/misc/jquery-ui-multiselect-widget-master/src/jquery.multiselect.js
Not sure what I shall do with them. Would you give me any recommendations, please?

Hello there,

To help checking if that issue relates to Airi theme’s code, try temporarily switching to one of default WordPress themes. Then re-run your test.

Regards,
Kharis