Admin not loading, website not loading

In wp-config.php page, change the define(‘WP_DEBUG’, false) to define(‘WP_DEBUG’, true) to see if there are any errors.

As above, you can try activating debugging (https://premium.wpmudev.org/blog/troubleshoot-white-screen-errors/)

If all else fails, rename /wp-content/plugins to /wp-content/plugins_old

Test site

Then create a new, empty folder /wp-content/plugins and copy each plugin back in (from plugins_old) until you identify the problem