HTTP ERROR 500 (Activello Error Log)

Hello!
Please help …
I have not been able to access my page (WordPress) or even the site administrator for more than a year.
I had the brilliant idea of ??doing an UPDATE of the WordPress version, Activello Theme and all the plugins without making a copy of the database before. Yes, I know, the worst idea ever…
Since then, both the url of the web and the admin show an error.
https://madein1980.com/
https://madein1980.com/wp-login.php
I have tried EVERYTHING! From ftp, rename the plugins and themes folders within wp-content. Change the PHP, enable and disable the boost from the service provider … I don’t know what else to do anymore.
I have managed to have an error log when accessing the web, in case it would help:

Notice: get_settings is deprecated since version 2.1! Use get_option() instead. in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/functions.php on line 3573 Notice: wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. Please see Debugging in WordPress for more information. (This message was added in version 3.3.) in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/functions.php on line 3792 Deprecated: Function create_function() is deprecated in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/pomo/translations.php on line 208 Deprecated: Function create_function() is deprecated in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/pomo/translations.php on line 208 Deprecated: Function create_function() is deprecated in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/pomo/translations.php on line 208 Fatal error: Uncaught Error: Call to undefined function wp_update_custom_css_post() in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-content/themes/activello/functions.php:125 Stack trace: #0 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-includes/plugin.php(525): activello_setup(”) #1 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-settings.php(376): do_action(‘after_setup_the…’) #2 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-config.php(88): require_once(‘/mnt/web006/c2/…’) #3 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-load.php(37): require_once(‘/mnt/web006/c2/…’) #4 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-blog-header.php(12): require_once(‘/mnt/web006/c2/…’) #5 /mnt/web006/c2/08/57253708/htdocs/WordPress_03/index.php(17): require(‘/mnt/web006/c2/…’) #6 {main} thrown in /mnt/web006/c2/08/57253708/htdocs/WordPress_03/wp-content/themes/activello/functions.php on line 125

Please help me solve this issue because I am already desperate.
Entering the WordPress app on the phone and WordPress.com does not show my website entries, nor the uploaded files, nor plugins … but within the FTP there is all that info within the wp-content.
I am not an expert on the subject and I have limited myself to following all the advice that I have read in forums, but nothing works.
In the worst case, I would be willing to start from zero with my website / blog, and try to recover the entries in some way.

Many thanks in advance to all!

The page I need help with: [log in to see the link]